I want to cry but I wont show that I am down for him

Well I known this guy since 9th grade and I fall in love with him. Now he is 12 and I am in 11 so he is leaving my school. I want to cry but I wont show that I am down for him. So last he was about to kiss me but he didn't because my friend told me he had a girlfriend so I didn't want to be the one he is doing the bad thing with so I take my self of it. Now he is leaving I am trying really hard to get him and i think it's gonna because things and things I just don't really know what to do about it. And he is my class right in way of me and I keep staring at him. His hugs are the best by the way.