I love my boyfriend, i'm obsessed with him even though he treats me like crap, i don't know what to do?

i am 18 and my bf is 19, i would do anything for him, there isn't 5 minutes of the day that i don't think of him, it's crazy... he has cheated on me at least 5 times, we've been together for 9 months, he hits me sometimes aswell when i stay out late, but in a messed up way it makes me happy cos i know it means he cares for me .. he tells me he loves me then i find out he has cheated on me .. i know it is wrong and my friends and family think i'm stupid but i love him and i can't let him go, it hurts me so much but he is a ****, but i love him :@ :(