Stay positive, buddy.
Maybe it wasn't you.
Maybe she was kidnapped or died or hit her head and lost her memory.
There's all kinds of reasons.
HEY, maybe she was a serial killer and decided against murdering you 'cause she liked you so much. Unfortunately, you two could never be because she knew things were going to end badly for her and she didn't want to put you through that.
See, all kinds of reasons.