How can I get the man I love out of my mind and heart?

I have known this man for 3 years. We became best friends with benefits if you know what I mean. We had discussed dating, but he said that he didn't want to destroy what we had. We got along great and everything was fine until Sept. of this year. He met a girl who he started dating. Of course our intimacy ended and so did our friendship because I can't handle watching him with someone else. I am in love with him and I wanted to be more than just a friend. I haven't seen him since Aug. but we have been talking on the phone. He offered me financial help for Christmas on the condition that I meet his girlfriend. When I refused to meet her, he took back his offer. That hurt me so bad. He knows how I feel about him. He says that we were suppose to be friends first and foremost and that I let my heart run away. Maybe he is right, but I can't help how I feel. He consumes a lot of my thoughts. I cry myself to sleep at night and I feel very lonely. How do I get him out of my heart and mind.