What do I do? All the fat jokes are getting to me.?

I have ben bullied at school for a while now ( like 3 years) but as I get older, I know that I'm more self conscious. I'm 13. At school we were watching a documentary about whales. Some kid yells out "Hey _______ you're in that movie!". I felt like crying so bad. Then there were other jokes and my crush even joined in on them. I tried not to cry and it worked. My eyes got a bit watery but I just start to hate myself more and more everyday. Every morning, I spend an hour trying to pick out clothes that make me look "not that fat". What can I do to make myself feel better? PLease help