So i like this guy and I don't know what to do?

So I've known this guy since fourth grade, we would hang out by the playground in the summer time when our parents couldn't watch over us and they had to work, so we went to Daycare. We were weird in our own little way he said stuff without caring what people thought, I was sort fo awkward. As we got older we went to middle school together and we had the same homeroom and then we went onto high school. We had the same homeroom for one year and then he switched out of the honors academy. We still had maybe one or two cles for most of the years and if no cles then we had lunch together with our group of friends. Then junior year came and he told me after a long test we had to take, he said "Hey I'm moving with my father, things are turning into hell living with my mom. So I'm going to finish high school out there." I was crushed, I still am. He was the one guy who I always cared about who in returned cared about me, and he left to live with his father. He looked happier when we hung out with a few friends and he looked happier. He talked about his new girlfriend who didn't seem so pleased about, and when we dropped me off back home we hugged each other and told each other good-bye. I didn't want to keep him waiting he was driving home others as well, the next day my friend told me to hang out so I did. She looked at me and said "Did you noticed how he looked at you?" I was oblivious. "He looked at you so much differently then any of us, he has this look when he sees you." I laughed and then my friends said the same thing. For the longest time I've truly liked my best friend and I've known I've been to selfless to take him from his happy like and his relationship with his girlfriend. What do I do? He doesn't live in my city anymore, and he has a girlfriend, and I have no way but AIM to contact him with..