Labels are thrown around a lot and it really takes a professional to determine what the actual diagnosis is. Can't really go by what you've told us to even make a guess as it could be BPD or some thing else entirely different. She could even have more then one disorder too. I think the thing we can all agree on, labels aside for a moment, is she does have issues and she should seek a therapist. Other then that you have two choices. Try to be as understanding and supportive as you can, or get out now, because things could get worse, or stay the same indefinitely and yes even get better, but the first two are more probable.