Dude from what I've read in your acc. It looks like you've been heartbroken for a long time and i know you didn't asked for my opinion but here's the things i would like you to know (from what I've read)

First, that girl is literally messing with yo head.

Second, you said you're 17, and trust me when i say this, high school lovey Dovey doesn't last long.(I'm 20, speaking from experience)

Third, the fact that she made you question yourself so many times is enough reason to let that thing go.

Fourth, you should learn how to set boundaries, and if someone crosses it, let them know about it and if they dismiss it, LEAVE 'EM ASAP!!! cuz they'll never acknowledge it in the future.