I need help getting over an extreamly bad breakup?

Let me start from the begining. I met this amazing women named Sylvia. We was so close. Every basketball game we went into a different wall way just to get away from everyone else. My first kiss with her was absolutly amazing. The reason why we broke up was because of our parents. Her parents hated me and my parents hatted her. I miss her so much. You have no idea. But she hates me now. I can't go back with her no matter what. We used to watch Titanic all the time with each other, our favorite movie. Everytime I hear the song "My Heart Will Go On" I cry my eyes out. I really deeply loved her and part of me still does. I need real help. I need to get over her. It's been 6 months since she told me she hated me. This is why she hates me: During a football game, she's in the band playing, i waited for her at halftime. During that time, the band gets to get a quick break after the show. At this time, both our parents didn't knew we was still dating. She came to me and she was looking for her dad to make sure he wasn't there. I yelled at her, thinking she didn't want to do anything with me. I then said whatever and went away and sat down by the fence. Her friend Luara then came over and said "come on, talk to her." When I did, Sylvia was crying so hard. I had never made her cry, until that day...My soul that day broke in half. I knew it was over. I've been cutting myself ever since. I really need help. We were even going to get married. I ****** it up and it's all my fault. Please, I am begging you, someone help me. I really do not know what to do anymore. Someone take this knife away from me. I have lost all faith and hope.