I don't think we could jump to bipolar based on her being on and off about the relationship. I more get the feeling that she doesn't want to be with you, but wants to keep you on the back burner just in case. She wants her freedom and her back up. I think you did the right thing. This relationship is totally unhealthy and you have other issues to take care of. Vent away any time. I'm sorry you have to go through this.