Depression Support Group
Depression is a real and debilitating condition that is often misunderstood by family and friends. Its meaning can range from a prolonged period of sadness to an actual mental illness with specific symptoms. Find and share experiences with others who are going through the same struggles.

If you really fear for your life you will go. Just get it documented and find out what the deal will be if she follows you there. Get that locked in.
If you can't control her access to you (ie staring at you, being in the same study hall, .. ) then work on taking away her power over you. I don't know all your issues with her, but here are some things that have worked for me when dealing with difficult people. (I will let you determine just exactly what 'difficult people' means!
Don't try to get them to agree that they are being jerks, and do not wit for them to apologize to you. In an ideal world they would realize how bad they are and apologize to you; in fact in an ideal world they would never treat you that poorly in the first place.
Document what they do to you; the AP may not be inclined to do anything about her attitude, but if this person ever touches you, that is a different thing. Include time, date, location, and people who were there. Especially the names of people who will tell the truth.
I know that ignoring jerks is hard, but it is often the best solution. Like RJW said, bullies thrive on your reaction, and if you don't give it to them they lose interest.
Look within you for things to do to divert your attention to them. Seek out people "like you" (what ever that means!) and start to form a bit of a social network.
Gentle hugs