Stocker Issues..........

Does anyone have any advice to get rid of someone who stocks you? He wont leave me alone, he comments on all of my things, stares at me all day at school, follows me every where wont leave my Boyfriend alone......He actually stocks me, im not just saying this Because i'm in high school and a guy pays alot of attention to me...No, He has been inlove with me for three years and when ever me and my boyfriend (and past boyfriends) kissed he would stare and when we wanted to go somewhere alone he would follow even if we asked him to go away. He gives dirty glances to any boys I talk to and tries to look like a fool infront of me to get my attention. Besides that he screams at me for no reasons, he yells when ever I make a joke about something, and when someone else makes a joke and i slightly Giggle he screams at the top of his lungs at me for giggling. And he openly admitted to masturbating to me...which is gross...and he always stares at me creepily and he looks for me in the mornings. He calls me all the time (I ignore his calls) and he just wont stop, I even tell him to stop, I tell him to leave me alone and just screw off and he wont listen. I was told this is emotional abuse because everyday in the hall Me and all my friends(who he thinks are his friends too -No one likes him because he's an ass and annoying) We have to look out for him in the halls. Its really annoying. Im getting tired of this. The other day he wanted to know what university I was going to and to see my courses so maybe he could get a class with me...It needs to stop...