This guy picks on me, help!?

Ok, so there is just a total ****** at my school, I hate his guts! I've had issues picking on me all year, only a week left, but I wanna stand up for myself. So I think I'm a nice guy, I'm nice, I'm really shy due to bad social anxiety, I have severe depression and this guy is making it worse! So anyway, the guy I despise is named Bryan, maybe Brian, idk. He's definitely the preppy jock kind of guy, I'm the quiet kid who has pretty much no friends. Whenever he sees me he'll ember me somehow or draw attention/make fun of me. He likes to insult me for being a hippyish kind of person, he REALLY likes to make fun of my clothes which aren't even weird, I wear flannel shirts tees and jeans. Ya were different, he usually wears a polo (he likes pink alot oddly) khakis and for some reason tucks his shirt in all the time. But he is SO mean, most free periods he'll walk up to me, and takes advantage of me not being strong, I'm very weak, and he just grabs onto my elbow and won't let me go, and he'll try to socialize, but sarcastically to make me anxious. And if he wasn't so mean I'd like to be his friend, but I'm always too timid to talk, and the fact that we hate eachother. Please help!