Why is he avoiding me???

heres the story, Then:I met him two years ago and he is a grade lower than me. The school we used to go to was a private school with a very small number of students so everyone was very close with each other. Well I started to like him in 9th grade up till now, and I really like him. During the summer we would see each other at parties and we would text each other everyday. I totally thought he liked me. Then when school started again, we are both in public high school now with like a million more kids, whenever he saw me he would smile and wave like he was happy to see me. We didn’t text as much as we used to.

I had told my other friend that I liked him, and she was trying to get him and me to hang out with her and her boyfriend, like a double date. and Uggh, I stupidly let her ask him if he wanted to hang out with us. A girl he hasn’t even seen before just asked him to hang out with us!! So then next day when my friend wasn’t there, I was walking home with him and he asked me “where is your friend?” me ,”oh she left already.” and then he says “she is weird.” and I am thinking, yeah no kidding! he said it like he meant it.

Now: he never replies when I text him unless I ask like a question.(like, I will say hi! and he won’t reply)Oo, that rhymes(and I don’t just text hi all the time, I say other things)(and this has been going on for like 3 weeks) He doesn’t smile when I am with my friend. He barely smiles at me at all when we pass each other in the hallways. And He never looks me in the eye when I talk to him or should I say ‘if’ I talk to him. We barely talk

Why is he being like this?? Why is this happening? What do I do? no rude answers please, thank you!!! :]