How Do You Heal A Broken Heart?

I dated my best friend for about 3 years. When my life was spiraling out of control he came out of nowhere and helped me. I never saw him that way until we got super close and then one day we went from best friends to dating. But we stayed friends and well we just clicked and got along. He was good for me. But not for long. We had a rocky on and off relationship and it really messed us both up. Made him more colder and angrier and made me more sad and distant. We began to fight more and soon we would spend weeks apart, pissed at one another. But I never stopped loving him. I loved him so much. Too much I thought at one point. And we kept trying to save the relationship by going back out and giving in one last try, saying this would be it and we'd make it. But...we never did. And he made so many promises to me. I'm 17 and still in high school so I have to see him all the time and it tears me up. About the third year he got more distant even while we were dating. He stopped calling completely, only texted me when he was bored, was always busy and never really talked to me much but since we had so much history and cause I loved him so much I brushed it aside and stayed. But it got worse. Really worse really fast. We broke up because he was treating me badly so I dumped him and yet we did things together which though it's my fault only made me love him more oddly enough. But then I found out he was only using me. For about the last year we were together he was using me. It meant nothing to him really. And then it all happened in a sort of domino effect. One right after another he betrayed me with something that felt like a slap to the face. And before he did all that to me he just stopped even talking to me. He ignored me, barely looked at me and would avoid me and I was so confused! I thought we were still friends, still trying to work it out, but apparently he was already ready to move on, forget me. But he never told me until I asked him and he just said he was over me. And that was it. I was shocked but surprisingly okay. I guess I was just too tired to care anymore. But still. We went out seperate ways and I wished him well and told him I'd always miss him. But then the betrayals came and he broke my heart. I couldn't believe it, wrap my head around how he could do that to ME. The person that was always there for him, always loved him, always honest and loyal to him and he betrayed me. I confronted him twice about two things that he did to me and I just lost it! I freaked out on him. And he said he never meant for it to happen and that he would leave me alone. We parted again. And for weeks I was getting better, okay without him, and he ignored me like always only this time it didn't hurt as much. But then I started thinking about him more and started missing him like crazy. I just couldn't erase 3 years of history. Couldn't let it be over. So with advice from my best friend I pulled him aside to ask him if he was okay. He wasn't. He was very sad. So like a stupid girl I umed it was because he missed me. But then soon enough a week after that we started talking again, like magic. And we began to act like we used to, like good friends, teasing and joking and he even seemed to go back to his old self and treat me well. We even started flirting. And I knew in the back of my mind I couldn't be with him after all he'd done with me. But I couldn't stop falling for him. Again. Or at least...liking him. I began to feel things again and then...I began to realize one night that I shouldn't care about him, after all he'd done to me. That it was time to let him go. So I did. I began to ignore him, p him by in the hall. And it sucked. But I felt better day by day, and I thought I was okay, I was finally getting better again. But then just last night my friend called me and told me that he was dating someone else and it killed me! I don't know why or what to do! I know I don't love him but three years is so much time to just forget and erase to me. He was the first person I ever loved, or let in, we did everything together and we close mentally and physically, so this has really left me messed up. I'm humiliated and broken hearted because I hung on to every promise he made me only to find out he found someone else and I never meant that much to him. It cuts me up. And I just want this pain to go away so I can finally move on with me life. But even though I'm strong and I have great friends I feel so alone and betrayed and hurt and he's the only one I want. I don't know why he did this to me. Why he thinks it's okay. Why he just stopped even talking to me, like we never meant anything. And I know it's life and time heals all wounds but honestly I'm scared it won't. Three years makes an impact especially when you never felt that way before. He came into my life at the best time and really saved me. So now my heart feels a