Was everything I did meaningless?

We were together 3 years. She was amazing to me I thought she was beautiful and most precious thing. She kept hurting me knowing I was in love with her. Dumped me 9 times and didn't treat me very well. I guess everything I did all my promises didn't matter right? Well in October I gave her time to think like she asked and in 3 days she had a new boyfriend. That crushed me. Well that entire relationship she kept telling me she loved me and wanted to be with me and they broke up got back together broke up again. When she promised we would wok on us. Well this was her fault but I love her so much. Don't let go of someone you can't go a day without thinking about right? Well there's a new guy and I want us to get back together it wasn't all bad. Well I told her about promises she made and she tells me it's my fault. That she doesn't know if she cares. I keep wanting to talk about it and she ignored me or said not now and there's never a time. Does she enjoy hurting me knowing I tried and did everything for her. I said what about what she said while dating that other dude she said well I changed my mind. It's so messed up about what she did to me. Now 4 girls wanted to date me and I waited like she asked. Fack! I promised not to tell who but she said I guess your promises to them are more important to them than me but yet all those guys were more important than me? She doesn't care she never did. She doesn't try or want to talk it out I'm hurting myself. I don't know what to do I'm breaking completely down because of her. I can't stand it her not loving me and liking someone else and I didn't do anything wrong I did everything she wanted does nothing I did count all the things said count! What do I do?