Is it my fault the friendship is over?

Well unlike the other answer i actually read what you wrote. NO its not your fault. If anything it is her fault.You let her know how you felt and if she felt the same way she should have let you know instead of pushing you away and then going back. I actually think she has led you on because she knows how you feel and I feel like she's just messing with your head. I think you should keep talking to her as a friend and don't get your hopes up. Go out with other girls and try getting her out of your head. I know it might not be what you want to hear but I honestly don't think you should spend your time just waiting for her. What I've told you is based on what you wrote and I really think you should consider what I've said. Just be her friend and make yourself available to other women because she might not be the one for you in the end.