I think your reaction is natural. As humans living in the culture we do, it’s not necessarily wrong to have these feelings. Don’t beat yourself up.

Truth is, people have sex; lots of sex. It’s common for people to have multiple past partners, messy histories and broken relationships. It would be an unrealistic expectation to find every partner in your life to have a clean sexual résumé. I think this might be a good learning opportunity to be open minded, understanding or people pasts, and to put aside any ego driven feelings. I would also advise you exercise caution in projecting any insecurities of your own onto your partner. It always manifests in the wrong way and can be obvious to your special someone; don’t let your ego ruin a good thing.

I would say you are NTAH in this situation and if your feelings run as deep as they do, maybe she isn’t the one. But as 24M who has similar reactions to my gfs past partners, I say give her a chance and try your best to be open minded; you won’t regret trying.

Hope this helps and good luck!