What a distressing and confusing situation this is for you. It sounds like you believe her issues have to do with some of her past relationships, but you are not sure. Her issues may have to do with other things, maybe from her childhood or just within herself. Until you know for certain, do not assume. Just accept that she has some issues she needs to work on and that she will tell you about it when she is ready. If the meantime you need to take care of you. All we really have any influence on in a relationship is ourselves. Work on being your best self. Take a break from thinking about her and her issues. If you need to go to counseling/therapy to do that or just for support, do it! Take this time to focus on you, being your best physically and emotionally. Think about what you want in a relationship and in your life. Take up a new hobby, take a class, take a trip you have always wanted to take. See this as an opportunity for yourself as well as your relationship with her.