I was my girlfriend's 9th she was my 1st this upsets me & i'm not sure how 2 accept it...?

I was my girlfriend's 9th she was my 1st & i no all d bois she has slept wid n her reason but alot of them where rly pathfetic e.g. she liked sum boi but he was gettin with another girl so she slepted with his mate 2 piss him off, so pretty much my girlfriend use 2 b a slag & it upsets 2 no that she has slept with other boys & 4 pathfetic reasons like not even boyfriend girlfriend just random boys she isn't like this now she has changed alot & she even realises that she was a slag & now has sort'd herself out & i trust her now cause she is not like how she was she is a totally diffrent person but her past makes me upset & it hurts that there isn't anything i can do that can change it, i get pissed off/upset bout it alot i can't help myself from thinking bout it. part of me feels like i want 2 go sleep with 8 over girls so that i can feel even so like i wont care that she has slept'd with other boys cause i would hav slept with over girls, but i dnt want 2 hurt her i love her 2bits but i rly do hate her past & i can't change it, so i think if i shag others den i will feel even & wont care bout her past its like i feel like this is the only way 2 accept wat happened i cnt think of anything else that i can do can sum1 plz help me or giv me advice i dnt no if want i am thinkin of doing is the right thing 2 do or wrong