Why did he used to like me but not anymore?

Before i looked at him and smiled, i never even knew who he was. He then inboxed me on facebook asking if i had bbm (blackberry messenger) i said no i've got an iphone, he never repled then 2 weeks later i was on facebook and he inboxed me again and started talking, we didn't talk much before he said he was going to sleep, i gave him my number and he straight away text me, so i saved his number, he was calling me princess and stuff so i thought he liked me. We used to rarely text eachother but he smiled and winked at me in school. Well we no longer talked and seemed to have drifted. He didn't come to school and i found out that he got kicked out of school. I felt heartbroken and can't stop thinking about him, i try to text him and he doesn't leave kisses or want to make conversation. Why doesn't he like me no more?

It doesn't sound like it was anything serious to him. Maybe he didn't like you and you sort of exaggerated things in your head. Don't read into things too much, it does end up getting you hurt sometimes.

Maybe all he wanted was someone to flirt with or make him feel special, but not a serious relationship, and you made him feel like you were really too clingy for his interests or something. You might never know. All you can really do is move on, if you don't talk anymore.

It sounds like its not that much about you but that he's preoccupied with his life, decisions and mistakes, maybe there's stuff going on in his life etc. Just keep being friendly, show him that you care
and eventually he might make a move, good luck!