My current gf is a slut. It's cool for the sex and all but I can't help but feel bad when I think about all the dicks and cum that went over her.
What do? :( How to change my mindset?
Break up and then open your mind.
Try and see where's she's coming from.
Do not allow your prejudices influence your actions. Remember that it's not anyone's place to judge another, even if we all do it by default.
Quit being a bottom bitch weeaboo faggot pansy ass pussy whipped sissy fuck? That's my suggestion. Man up and start dicking other girls or tell her to quit wasting your time. She's using you as an emotional crutch and manipulating you with sex in her disgusting and vile holes. You need to quit being a dumbass.
This desu, OP
It's one thing if she is continuing to have sex with other people while you're dating-- then you're completely justified in being upset and should leave her
If it's just about her past before you dated, get the fuck over yourself