I fell in love with my best friend. (long sorry!)?

I don't even know where to begin. Well we became friends in 5 grade. (we're currently juniors) I had other friends and I didnt speak too him very often back then. When we reached middle school we beame closer and he asked me out a few times. But he was 'chubby' and I was embarrassed to say yes even though I liked him. It was childish that now I wish I could go back and slap myself. Anyways, when we reached high school things changed even more. He stopped flirting with me and became what someone would call a man whore. And dispite (spelling?) the man whore part I fell in love with him. And I guess it showed because he started to flirt back and make comments about us being together. I hoped so much he would ask me out. And one day we were in his room and he almost kissed me. His brother walked in. ): and then someone told him I loved him. That ruined everything. He has stopped talking to me. Now we aren't friends anymore. It breaks my heart when I see him. And I automatically hate the girls he dates even if I know they don't deserve it. And now he likes my sister. MY SISTER. And I have no clue what to do. I'm sorry I'm rambling. And this may seem pointless to you. But it's important to me. And I may seem naive, but I've been through more than you could probably guess. So, please just tell me what you would recommend me do. And please keep the nasty comments to yourself.