How do i work out my problems with this guy?

i ahve liked this guy at my school for nearly four years now and he liked me last year, then he stopped liking me, i think, and now that he found out i like him he doesnt talk or hug me anymore, all he does is look at me for a second then look away, i want to know wat his actions mean, for example today at school i was walkin to the car and he was walkin about 7 metres ahead and he looked back to see me walkin behind him then looked away, does this mean that he DOESNT want me to like him or what, please help, :D