An ex of mine would do this. Not while we had dated but she told me how she would keep going back to the man who assaulted her. She would even initiate sexual activity with him. I asked her why and she explained to me that it took her a long time to realize he was a rapist. That the more she made it feel like it was her decisions it made the assault seem ok because they had a "relationship"

This led to a lot of messed up mental stuff for her. She self harmed and had massive panic attacks. She always blamed herself for what happened and it took a lot of work for her to see him in his true light.

My advice is this. You're not her caretaker nor her therapist. She might need some major help and if you choose to make it your responsibility to help her then you have to be in it 110% regardless of what she does. Its either that or you get out as hard or impossible as it may seem. Its better for you both in the long run.

I really feel for you. Good luck.