What can i do i hate her!?

There's a girl at my school and shes mean and a brat! I told the teacher but she cried! She was faking, and laughed after she got away with it! I was so mad i wanted to hit her! Now i have to stay in for recess to talk with her! What can i do to calm me down im soooo mad i hate her soooooooo much!!!!!! I have never hated someone so much!!!!!!!!!!!! it ticks me offf!!!!!!!!!!!!!!!!!!!!!!!!