Confused and in-Love

I am 16 years old. When i was in the 6th grade, I met this guy named Alex. He liked me in 6th grade and we even flirted back and forth and went out. In 8th grade we broke up after i gained weight and we didn't see each other a lot. But now that I've lost the weight and started wearing make-up, I found myself start to like him again. But he doesn't seem to know i exsist. What can I do? We talk online but he seems to hate me in public. How can I win him back?? **Edit: I talked to a bunch of friends today at school, and one that hangs out with Alex and is dating Alex's best friend asked me why i didn't just ask him out. Later, the tomboy in Alex's clique told me that him and me should get together and even tried to play matchmaker. What does all this mean? I don't want to read the signals wrong and humiliate myself :( HELP!!