I'm sorry, Kit, this sounds really hard. Obviously I don't think it's your job to educate her, and I don't know that you would be able to anyway, given that you aren't a mental health professional or a professor. I think the way her feelings mix with your feelings and the way she chooses whatever boundaries she wants whenever she feels like it are both big red flags. Sometimes we walk away to protect ourselves when something doesn't seem right. That isn't "running away" and not dealing with things but rather recognizing that we need something different in order to properly care for ourselves.