Oh god. A bit over-the-top is putting it mildly. If she won't get help I don't know what you can do. Learn how to communicate and defend yourself better could be a start. Sounds like protecting yourself is the only option unless you can get through to her somehow. If you have any insight into why she feels so strongly about how "bad" you are it could be a start as well. Sorry to hear that, it sounds like a real horror story.