I can't get this thought out of my head, help?

Ok so my girlfriend and I have been dating for about a year now, we have a good relationship. I mean we've had our issues but who doesn't ? Well for starters I'm a female as well. My girlfriend was the first person I let make love to me, it was amazing. The only thing that gets to me is that I wasn't her first, and that really kills me. I hate that I'm so traditional like because I really wanted to wait to marriage to have sex, but I felt she was the one. So I gave her my everything. She had all of me, but what bothers me is someone else has had her. It makes me really sad/upset because it's nothing I can do about it. Sometimes I'll sit and even visualize what she and her exes did.. 😭 I hate it. She always says she made a mistake by giving them her, and she should've waited for me. That doesn't help anything tho. It just make me feel like I'm another stupid statistic now, because everyone now is having sex! I waited until I was 17 I guess that's still not the greatest age, but compared to everyone else I know that's a long time to wait. Now that I'm 18 and I whole year has passed I still can't get the thought out that someone else has had sex with my girlfriend. It hurts, and I know I'm just being an insecure wuss. I just don't think it was fair ya know I wanted to wait and give my sex to someone else who was virgin. Ya know to make it special, because it would be two people who love one another, showing each other something really special for the first time. But I didn't get that special feeling of being her first because always in the back of my head it would always be that her exes had her first and not me. 😓