Hi raaddxx
I agree with the previous posters - you sound like you're in over your head with this friend. It's great that you're concerned about not worsening her issues, but with all her compulsive lying, trash talking, stalking and blaming you for her problems, you need to concentrate on yourself and putting as much distance between you as you can.

I'm not trying to be extreme, but she does sound like she can easily become dangerous. I'd suggest sharing what you've said here with your parents and hers (I'm not sure of your age), trusted friends and that counselor she may or may not have spoken to. Also change your locks and/or remove the spare key so she's not able to pop up in your room again.