I (30m) have been on an exclusive FWB relationship for more than 1 year with my (34f) long-time best friend, are we a couple without a label?

I met S while playing video games online and I really liked her from the first time we talked. We had a lot of fun playing and talking through Skype. We started talking daily about our days and our studies, and she got me into watching anime, which I really, really enjoyed. I started getting attached to her. The thing was, she was in a relationship and we lived in different cities, so for a while, the only thing I could think about was, "I wish she would just break up with that asshole (yes, the guy was never a very decent man) and be with me." But at that time, I decided to move forward, and our friendship went nicely; she even helped me with advice when I got a girlfriend at university. That relationship was a one-year nightmare for me, but S was there for me and helped me a lot through it. During this time, she moved to my city because of her job, and we could see each other more, at her apartment or going out to eat, but she still had her boyfriend, so everything remained just as friends. Even though I felt a little spark, I decided to ignore it.

A few months later, I met another girl and wasn't sure whether to start a relationship with her. S advised me to reconsider it if I wasn't sure, but I went for it, and things went really sideways for me for five years. S started distancing herself from me until I felt like we would never speak again, and our friendship was on hold for almost two years.

I finally broke up after five years, and the first thing I wanted was to see S and talk to her. So I reached out to her and asked her out for dinner, and she said yes right away, which surprised me because we hadn't talked for a while. We met after work, sat at our table, had a little chat, and I just couldn't hold back and said that I had broken up. She replied by telling me that she had been cheated on and ended her 12-year relationship . We held hands and cried a little bit, and told each other that, as painful as it was, we were determined to overcome this. (She already started a therapy about it)

We have been friends for 10 years, we have helped each other through ups and downs, and we have never had a fight or gotten mad at each other. After our dinner, we started talking daily like when we first met. We began seeing each other more, and after 2 or 3 months, she asked me to be exclusive friends with benefits, with no pressures. She said she would really like that but also made it clear that she didn't want a relationship because she was very hurt by what her ex did and was afraid of being cheated on again (she even mentioned this to me again a few months ago).

One year later, after one abroad trip together, taking care of each other because of medical issues, several weekends spent traveling, camping, going to resorts, long weekends at her place cooking together, playing video games, watching movies, several date nights, and lots of amazing sex, we are here enjoying our special relationship. But I think I'm really falling for her.

She says she's not the one for me because she feels she still needs to get her life together because of her ex, and she couldn't give me all that I deserve. For me she's a wonderful woman, great values, she's hot, we can talk for hours about anything, she's always there, talks to me about her things, and asks and helps about mine too. We see each other 2, 3, or even 4 times a week since we started this, without exception. I try to understand her and give her space, but I'm afraid of her leaving me. I'm afraid of her meeting someone else and ending things with me, or that the fact that I'm falling for her will upset her, and she'll decide to stop things because of this.

I would really like to know how do you see this, have you been in something similar?