Hey, I think it’s fair to say that his reaction is just coming from the fact that he thinks that you’re being rude to him. So he’s just reciprocating. And if it’s a crush, I can understand that feeling when they’re around. It gets very awkward and I think I’m stupider than my usual self around my crush. 
If you think he isn’t too much of a dick, maybe you could even tell him. That the cold shoulder is coming from a space of you liking him and not being able to express it. And then you could see from his reaction if he feels the way or if he is mature enough, he’ll just say it’s okay if you like me even if I don’t feel the same way and that way you should be able to resolve it I feel. 
If you want to get rid of the feeling, then I don’t know what you should do. Because I personally found that very hard. It took me a lot of time to get over this one guy, years. What helped me get over him was when I stopped viewing him through rose-tinted glasses and stopped putting him on a pedestal and started rationalising his actions, which made me realise how flawed he is. And eventually, I got over him. Doesn’t mean I hated him or anything. Just that I stopped thinking he’s the bomb, and just made him a normal human being like anyone else.