Wait. Does she not trust you? Have you tried looking at her differently? Maybe she had trusted too many people in the past who broke her trust. (And her heart.) Maybe the last guy she loved, told her the same things that you did. "Don't worry honey, you can trust me." "Hey, I promise you I won't leave." Maybe she's pushing you away because she knows how this is going to end. (she'll be hurt again.) Maybe she's too broken to try again. Maybe she just needs some time (or forever.) Maybe she just needs herself right now. Or maybe someone who could love her better and remove all her fears away. But you won't understand that obviously. (because you won't stay.)