Trouble coming to terms

My girlfriend (21) and i (21) have been dating for roughly only two months, and it has been great, truly has. We took things pretty fast, meeting only about 2.5 weeks before officially dating. She's shown me nothing but true care and affection and I am beyond grateful for the care she has given me. However, I feel like there's something that's stopping me from truly accepting it and appreciating it.
We have remarkably different sexual histories. I only have 3 bodies, one long term gf, one hy, and her. She is sitting in the 12-14 range while only having one true other relationship.
Now i know that the past should be the past and it isn't like I should have expected her to stay couped up her whole life prior to meeting me, but I feel as if that difference is a lot. It seems as if she had a more adventurous adolescence than I did and the thought of her past sometimes makes me queasy. I am not sure if it is one particular thing or if its a combination of things such as
would others look as just the guy who got with the promiscuous one 2-3 years ago?
am i just the settle down after the wild phase?
should I be worried when we go out drinking?
Am i just going to be another number down the line
is she truly different now
Why do I always think of her past when certain things come up
In the short time we've been dating, its never been a real concern that she is cheating or will cheat, that truly is not a fear. I am more so concerned with my ability to not come to terms with her past and am wondering if I ever will be able to and if not, what that means for our future together.
for further context, we've both met each others friends and family's and all four fronts have been great.