I need advice 😫

Charlie (he/him)
This is not really TMI, but I don't have anywhere else to post it (I'm sort of new to eve.) 
Alright, so I just found out my girlfriend has been cheating on me literally since we started dating (it's barely been a little over a month). I honestly should have know better, because she's been around the block quite a few times (if you know what I mean) and we're only in highschool. But she's really nice and pretty and I really liked her. 
Do you girls have any ideas that would help me get over the pain of being cheated on? Thanks 😘