Crazy psycho chick, Who stalks me Options

[PunjabiMc16]

So basically i'm in my final year of high school and i'm 18. The thing is that i have a friend who's exactly that. Just a friend. We're not really great friends but we're not casual acquaintances either.
So anyways recently she started acting really really weird. She keeps going to my exes and asks them what type of girls i like and if i'm interested in someone. Then she proceds to follow me all around the college campus which is really scary. And its not just the sort of "Oh you were going here too?". She does it alone. She hides behind walls to see me. I never gave her my cell phone number but she acquired it somehow and texts me all day.
Anyways this was slightly disturbing but it never bothered me much. A few other girls had done this too however nothing this extreme.
Shit hit the fan yesterday when she punched my current girlfriend because according to her she's not good enough for me. And although people prevented her from hitting her too much it did scare me. To what limits is this girl prepared to go?

Help me RC