Danielle Collins has always been a fighter. She says she got her competitive fire from her father and that will to win was evident from the start. A coach even nicknamed her 'Tenacious D' in her younger days. 

But nothing could prepare the 27-year-old Floridian for what she would endure through the first six months of the 2021 season. After enduring crippling pain through the start of the year throughout her body, Collins underwent emergency surgery in April for endometriosis, a painful disorder in and around the uterus that can cause severe pain during a woman's menstrual cycles.

Collins has credited the surgery with her on-court surge since Wimbledon. Now able to play pain-free, Collins has reeled off ten consecutive wins across clay and hardcourts to win the first two titles of her career. Her breakthrough came two weeks ago on the clay in Palermo and on Sunday she captured the biggest title of her career in the 50th-anniversary staging of the Mubadala Silicon Valley Classic. 

Always candid and forthright, Collins sat down with WTA Insider after her San Jose triumph to reflect on her last six months and what it feels like to be playing some of the best tennis of her career. 

WTA Insider: You've won the biggest title of your career, 10 consecutive matches, back-to-back titles. It's a lot to process. Has it sunk in yet? 
Collins: I feel like it's still sinking in. To win this tournament with the history and the legends that have won this event before, I just feel very honored to have won this. I think it makes it even more special, so I think it's just all kind of still sinking and I still feel like the tournament's not over (laughs).

Champion's Reel: How Danielle Collins won San Jose 2021

WTA Insider: You finished the tournament playing an incredible level. You fired 54 winners in the final and finished +23 winners to unforced errors. You played a fantastic semifinal well, winning in under an hour. How do you think you were able to peak at just the right time this week?
Collins: Yeah, I think this is where playing against such tough opponents day after day over the course of the last month and a half for me has helped my game so much. I feel like each match I'm making little improvements here and there. Sometimes I take a couple of steps back in some ways, and then the next day I can take a couple of steps forward. 

I'm learning so much through playing more events and getting more consistent match play against tough opponents like I faced all throughout this tournament and in the previous tournament. So I just hope that going into Montreal, I continue to get this type of match play, this type of time on court, because I'm just learning so much and taking it all in.

"I think if somebody would have told me at the beginning of the year that I would win two tournaments back-to-back, I don't think I would believe them because I think before the surgery, that was just not possible and almost unimaginable."

WTA Insider: Are you surprising yourself?
Collins: I think if somebody would have told me at the beginning of the year that I would win two tournaments back-to-back, I don't think I would believe them because I think before the surgery, that was just not possible and almost unimaginable. 

But I think now I'm doing so much better physically. I'm able to perform on court on a consistent basis day after day and not have the types of issues that I was having before. So I do think in some ways I'm a bit surprised because one goal of mine was to win a tournament this year and to win two is just the icing on the cake. I hope I can end up maybe winning some more, we'll see. 

We still have some tournaments left in the season, but to win two back to back, and especially after going from Palermo on the clay to San Jose on the hard, I just think it's really rewarding for me. I spent so much time on my physical fitness and my strength training that I think that this is where that has really paid off.  

WTA Insider: You mentioned your surgery for endometriosis, which you had in April. You've said this week that you're surprised at how successful the surgery has been for you. Was there still doubt as to what your career would look like after surgery? Can you take us back to April and what your mindset was? 
Collins: I was a little bit nervous going into the surgery, but I luckily had a surgeon that was very experienced who's been practicing for over 30 years. Somebody like that knew exactly what was going on, was very confident seeing me right away, and that the surgery would only make things better, not worse. 

I got to the point where I could no longer manage without it. Had I not had the surgery, I just couldn't keep living my life like that. The agony that I experienced from my menstrual cycles and from the endometriosis is some of the worst pain I've ever had.

It was scary at times. Falling over on a court at the Australian Open and having to have the doctor rush out to help me because of the contraction-like cramping that I was having in my low pelvis and abdominal muscles. I used to get terrible sciatic nerve pain that would go all the way down into my foot where I would literally lose feeling and have stabbing pain throughout my spine. I just didn't know what was going on. 

"The agony that I experienced from my menstrual cycles and from the endometriosis is some of the worst pain I've ever had. It was scary at times."

I had so many doctors tell me that painful periods were normal. This progressively got worse and worse. I think as somebody who is so career-driven, I put my health aside because I was always just trying to get to the next tournament and trying to practice and train. I would just try to ignore it and take my anti-inflammatories. 

But it got to the point where the anti-inflammatories no longer worked and it became more and more physically debilitating. I would have flu-like symptoms, fever, throwing up, being in the bathroom for hours, not being able to get out of bed, being in so much pain throughout my body that it was impossible to play matches. Having to pull out of tournaments, having to retire in the middle of matches because of how sick and how much pain I was in. 

It was tough because without the surgery, they're not able to get a very accurate diagnosis because the imaging can only read so far into your body. Your uterus and where the endometriosis tissue grows often can't be detected by an MRI or CAT scan. 

So surgery was the only option for me. I just wanted to start feeling better. I couldn't imagine going back to how I used to feel after feeling so great over the last couple of months. 

WTA Insider: You said this week that it was a pain that you just thought you were going to have to live with for the rest of your life. What ultimately led you to get a proper diagnosis?
Collins: I had really terrible back pain against Swiatek in Adelaide. Had to pull out of the match. I was told to take a couple of days off, that it was most likely a strain from just how much I had been playing. I took 10 days off, didn't get any better. I went home, start practicing for Miami Open. I wasn't at 100 percent, still having a lot of pain, terrible sciatic nerve pain where it was causing issues when I was driving. 

I called my orthopedic doctor that I go to to get an MRI, and said your spine looks perfect. I just don't see anything wrong, I don't know why you're in this much pain. 

My period started the next day and I was in terrible agony. I went into his office crying and I said, I can't do one more day like this. So he got me in with the gynecologist and the surgeon right away. And four days later, I was in for emergency surgery. 

WTA Insider: After the surgery, when you were able to get back on court and start hitting again, was it like night and day?
Collins: That was the tough thing. For endometriosis, I think it varies, but for my surgery, they actually tore through my abdominal wall in four different spots: near the lower abdominal muscles near the hips, one through the belly button and then one up a little bit higher. So when they tear through that, it's a tear. 

The rehab, the process it was getting back on the court was very long, tedious, repetitive exercises to try to strengthen that muscle back up. The first couple of days after surgery, I was curled up in a ball because it's so painful. It's small, but they literally cut that area open. So it's just really, really difficult. I was pretty much on bed rest for a full week, so I had a really good friend of mine take care of me through the surgery.

After two weeks, I was starting to rehab again. Then I was slowly incorporating the strength training and got back on court two weeks before the French Open started. It was kind of a gradual build-up. 

And then, unfortunately at the French Open I actually tore my ab again in one of the spots where I had the surgery. I felt it when I was playing Serena. I maybe came back a little bit too soon and it wasn't quite healed properly. I had a Grade 2 tear in my ab after French Open and I had to pull out of the tournaments because I was going to play full grass-court season and then I couldn't.

So then plans changed. I went home and rehabbed for two weeks. I only got to have about three hits on the grass courts and I went out and played at Wimbledon. 

"Just being able to have the confidence that I'm not going to hurt it again. At Wimbledon it was a huge mental block for me."

I was happy to get through my first-round match, but it was also extremely frustrating because after you have surgery, you're really scared about injuring that area. But then after having surgery and injuring that area and then coming back, you're extremely scared of getting injured again. That was the biggest thing that I had to overcome in the last couple of months. Just being able to have the confidence that I'm not going to hurt it again. 

At Wimbledon it was a huge mental block for me. I think I lost my match 6-2, 6-0 and I just was hesitant on every shot that I made. But I knew I was not in pain after this match, even though I got whooped. I needed to get on the clay courts. I need to get more match play. I need to try to build up more match stamina so that I can see how far I can go, see how I do, and hopefully that will give me more confidence as I play more matches, that I can get through this. If I give myself enough matches, over time I won't be thinking about it every point. 

But you think about it with everything you do. So much of my serving, so much of my big-hitting, sometimes I'd get a ball and I'd be like, should I hit this one? Working through that hesitancy and that fear, that's a really big part of it. 

WTA Insider: Was there a moment when you were finally able to put that fear behind you?
Collins: When I was playing in Budapest, I was still thinking about it quite a bit. I had to pull out of the match because of my elbow. Then in some ways, because I was having a bit of tendonitis in my elbow, it made me stop thinking about my issue with my stomach and the surgery. It got me more focused on that. 

Then I played some matches in Palermo and I said, OK, I'm feeling good after playing Hamburg and Budapest and there's no pain in my stomach. I've got to be confident to take full swings at the ball and use my body here. I can't be doing this game, this hesitancy, and just constantly be like, Oh, should I hit this one? Should I back off this one? 

I think it's been pretty clear, like since Palermo and this tournament, I've just had full confidence in my body.

WTA Insider: What are you most proud of with your run in San Jose as you head into Montreal?
Collins: What makes me the proudest is just the fight that I've had every match. I've had bumps along the way. Most of the matches that I've played here have been challenging, Against, for example, Rybakina, playing from behind, being able to figure out a way to win. 

Today, having the second set not go my way after having two handfuls of set points and still having the fighting spirit and that self-belief. I think that's what I'm most proud of, especially with not having a coach.