Really crazy stalker help!?

im in 10th grade and this guy in 9th grade is totally obsessed with me. he waits for me outside the hallways for me and walks behind me and if i walk faster he runs to catch up with me. i never even talked to him before. he knows my name but when he talks to other people about me he calls me misty which is far off from my name. i have a bunch of my friends guys and girls go up to him and tell him to stop following me and i dont like him and he scares me but all he says is "im a schizophrenic!" i even had people threaten him to leave me alone! but he still follows me and waits by my locker. he also tells people im his girlfriend. (i only know this stuff about him because he goes up to my friends and asks them stuff about me which they dont answer but then they tell me when they hear something) everything he does creeps me out and i want to go to my teacher but im not sure they will beleive me because he might lie and say he doesnt know me and i dont have real proof unless i video tape him running after me and they might not care. what d you think i should do? this is really freaking me out!! thanks so much!!