Please help! Bully problem?

Hi I am in year 8 and I am tiny and a wimp well any way I was eating some jelly out of a cup when this dibshit knocked it out of my hands on purpose so I picked it up and threw it at him so he tried to kick me but I caught his foot and knocked him to the ground and he had to go to the nurse and I didnt see him for the rest of the day. This is very brave for me and I am scared because tomorrow I have school and I am afraid he is going to beat me up. What should I do?