How to not fall for a guy?

theres this guy, and he was my classmate. but i barely started getting close to him on the last week of school. and turns out hes really sweet and nice. and we got close fast! then we gave eachother a biggg bear hug. haha. i keep saying to myself that hes just my homie, nothing more. but then whenever he talks about a girl or something, i get that heartbroken feeling. I DONT KNOW WHY. but i can tell im kinda starting to like him. im trying not too, hes not really my type. but i guess his personality just really got me. and i cant like him, cause hes switching schools. how can i avoid falling for him before it gets bad?...