If she loves guys so much why can't she just let me walk out of her life?

OK without knowing either of you there is not much real advice possible. But I think that you don't really want to be free of her cos you care so much about her and before long you would contact her again even if she did free you. That's life/love for you it isn't easy but it is a hell of a lot better than any other option. There will always be tiffs between two people who are close as each one is seeking some measure of control over the other and each one only wants to give up certain ground which never quite coincides with the ground that the other is trying to claim. Is that sort of hard to understand ? I just re read it and realise that I didn't express myself terribly clearly. You are going to have this girl in your life for some time yet , she doesn't want to lose you though she may not want to be tied to you either , just try to tolerate her fickle nature , she is not a bad person just a confused person. Keep your own life on track and meet people do not become fixated on this girl she is not your whole life but she is part of it.