One could attempt to analyze her, but why bother? Her problems are so severe that it is almost certain that you could do nothing about them. Probably she could profit from professional help, but not until she is ready to acknowledge that she needs it. It may be that after a few years of rejection by many people, she will finally realize that she needs to make radical changes in her life. Meanwhile, the most reasonable thing for you to do is level with her and tell her that you are immediately terminating the relationship because it is disrupting your life and taking a toll on your peace of mind. Then, wish her well and tell her that for your own peace of mind, you do not want to have any more contact with her, and stick to it! If you continue to have a "relationship" with her, you will be facilitating her irrational and abusive behavior which will delay her addressing her problems. You are not responsible for her problems; she is.
This may seem cruel, but really it isn't. She may need to experience justifiable rejection from several people before she finally wakes up and takes action to get her head on straight. You cannot rescue everyone; be aware of your own limitations.
I myself was once a rescuerer before learning that it doesn't work, that I was facilitating destructive behavior, and causing problems for myself.