I want to tell him that i like him but i cant help ?!?!?

we use to talk alot in elementary probaly because we were in the same homeroom but during the summer we talked alot but once we got in junior high we talked alot until like the 2nd semester & now he literally walks p me in the hall and doesn't even look at me ! I like him alot though. I guess we are starting to talk a little again. I want to tell him i like him im scared though PLEASE HELP !!!!