You move on. You told him and if he doesn't feel the same way then you need to move on. That probably isn't what you want to hear, so sorry for that, but it is what you need to do. he might come around he might not but don't worry about it. There are way more guys in the world and you'll find one, one that when you say you like him, he'll say he likes you back.
If you tell me that you like me and I run away, what should I do? If the guy avoids you, it's because he's a shy one. What you should try to do is give him your phone number or arrange a secret meeting.