Crushes are horrible! I'm sorry you're feeling like this. If he and your friends are making fun of you, really he doesn't deserve you liking him. That's not an easy thing to realise or think about though. You probably aren't enjoying realising he's maybe not the person you thought he was or hoped he might be.
These things take time to go away. One day you won't feel anything about him anymore, but it might take a while. Until then you just have to be strong. Whatever you do, keep going to school. Don't let him impact your education, because he isn't important, but your education is very very important! Remember lots of people have been in your position. I still cringe at the day my crush laughed at my bright yellow woolly hat which I thought was so cool.