<human>: Can you provide a brief rundown of the text in within 3 sentences?

So there was this girl I met in highschool who was going through a rough time with her best friend dying. I took interest in her and tried to help her through this time. This turned into me liking her and eventually getting "friend zoned" which I don't really like that term but that's what you'd call it. She complained about all these guys to me so eventually I told her how I felt and she didn't give me a direct answer ever. So fast forward and I'm taking this girl to prom, I ask her all elaborately, buy her ticket, and she ends up banging two guys the week before prom. I thought she liked me and it destroyed me. So I stopped talking to her for a while and eventually we made up and kept talking just recently to just end up with me saying how I'm jealous and can't talk to her anymore. 

Basically, now, I was so attached to this girl that I don't know how to pick back up where I left off. I wasted so much time and was lied to so much that I have bad trust issues and low confidence. If a girl I like as much as talks to a guy I get all jealous. I feel like I'll never be able to get into a relationship without the girl having a separate agenda and it sucks.
<bot>: Girl I liked fucked me over by "cheating" when it wasn't official. Now I'm a jealous guy with no dating skills and low confidence.