Why do i care about him so much?

this guy "talks" to a lot of girls. but he doesn't do stuff with that many. he's had with 2 girls and done other stuff with 3 or 4. he's a freshman. i'm a junior. i've never done anything. me and him became friends. we weren't talking. and one day we made out, then we kinda stopped talking cuz it was weird. then i initiated a friends with benefits relationship. we fooled around once, then he told me that we shouldn't be fwb anymore cuz he kinda likes this other girl. i flipped out on him cuz i had asked him if he liked anyone and he said no, so he used me basically. then i got drunk (first time) and he was sober and i was so mean to him the whole time and then i was rambling about him saying he is nice to look at and has nice hair and that i was sorry for being mean and the he's like it's ok i'll text you in the morning and then he did text me and said he wasn't mad at me. i dk what to do about him