What am I supposed to do?

Okay, so I fell in love with this one girl, but I didn't think she liked me back. So I kept quiet for a while, but one day in January her cousin tells me that she likes me. I doubted this, because I saw her flirting with a boy at school. But I thought I'd try anyway, but kept my distance for the time being because I got so nervous when I saw her that it was hard to talk to her. Eventually she found out that her cousin told me, and thought that the reason I kept my distance was because I hated her (which I didn't). But the day I figure out what I'm gonna say, the guy who was flirting with her before asks her out: she says yes. Shocked and shaken, I fell from my fortress. She loved him more than she ever liked me, although we were best friends. Every day she was always next to him, being held in his arms and showered in kisses. And she always seemed to do it whenever I was near. Every Thursday we would all get together for our club, but since they started going out they just found a dark corner during the movies we'd watch and make out. She was acting like she was no longer interested in me, but we still talked over the phone. It was painful to see them fondling each other, especially with her denying my witnessing. It was like she was trying to keep a secret from me. And I grew tired of it. I tore myself up inside, trying to tell myself that she was happy, and I should therefore be happy. But as the days went by we grew apart, and whenever she promised to stay with me on Thursdays she would always go with him. Heartbroken, I told her about how sad and angry I was. She was not happy, and cried. I eventually apologized for my sudden outburst. So I stood one more week before her boyfriend graduated. With this came their breakup. Inside I was still uneasy, because I knew that she was just going to crawl back to him. So the last day of school, a Thursday, she FINALLY hangs out with me. And we have fun at the end-of-the-year party. Over the summer I went to Illinois for vacation. I would call her every night I could and talk to her, hoping to establish more than just 'friendship'. We got really close, but not close enough I guess. While I was gone, she told me that she met some weird guy on Face Book. We joked around about how he was probably some kinda weird pedophile or something. But eventually, they started to talk more. She gave him her phone number. Instead of the pulse of a phone ring I would more often hear a busy tone. I got excessively jealous. She convinced me that she was just his 'friend' and nothing more. But upon visiting her face book, I saw that she had said she'd "Made a new best friend". Well, I was pretty peeved. In fact, it drove me insane. I sent him a message about it, telling him how much it hurt me, but as Karma would have it all I got back was "**** you and deal with it", only in a more polite manner. She didn't care about the things he said, and I knew that she was just going to end up falling for him in the end. I was very scared and very sad because I didn't want to lose someone a second time, while not even being together in the first place. Eventually she told me that she liked him, and my heart shattered into a million pieces, where she then proceeded to super glue them to the floor. He eventually asked her out, and she immediately said yes. My life was over. I hated myself so much. And I couldn't even do anything because I was in Illinois. And he was in Baltimore, and to this very day has not met her in person once. I was planning on asking her out right when I got home, but at this point it was too late. Once again my diffidence had led to depression. He called her more and more, and I called less and less, and eventually led to almost total silence of both of us. I had just received the 'wonderful' information that I was ACTUALLY going to move to Illinois. I didn't want to go, but I got a week's reprieve to Maryland a week before school started. All I ever heard was how much she loved Ollie and how happy she was and how excited she was, and I guess for that I was happy for her. Sure, I was jealous, but I guess if I failed a second time then I was obviously worthless. But the one thing that really got on my nerves was that she kept talking about how her ex was coming back from the military, and how excited she was to see him, even though she was dating another guy (whom, again, she has never met to this day). She always tells me how excited she is to see him when he comes in December, and I'm just getting sick of it. She's dating one guy, likes another, and knows that I had feelings for her because she too once had feelings for me. But at this point I don't really know what to do, because all I hear is her talking about her ex and how he's coming back, and how her current boyfriend 'might' be coming on a certain day. I'm sick of listening to it, but I still love her. What should I do?