How do I get over this?

I've been in love with the same man all of my life. The thought of him in the back of my mind has ruined good relationships with lovely men and I wish he didn't have this affect on me.
At 16 I became pregnant with his child, but we had both had too much to drink and he didnt even remember sleeping with me so I only ever told my closest friends. I lost the baby naturally which was probably for the best.
Every time we see eachother he pretends to not look at me but I catch him looking before he can quickly turn his head. I'm so aware of him, more than anyone else in my whole life.
Last year at a party he said to me (infront of my boyfriend at the time) that I was his oldest friend, I'm the only one to have been there all the time and that everyone else has gone. That was totally out of character for him, he's usually an arrogant self assured person.
He's a very popular guy and sometimes I think why am I even bothering wasting my life hankering after him when he could have anyone! I sit and wonder if he ever thinks about me as much as I think about him. I just really really want to find happiness and give someone else a chance instead of going around in circles! What should I do?