Is this friendship?

Hello friends I publish this journal to ask you advice of what I should do, since you know me and I have several skills but I am a total failure in sports and exercise, these two days my classmates have been laughing at me , because the routines of the gym still make me very difficult and some girls who are supposed to be my friends, laugh at me, instead of helping me, they only attack me with shouts and demotivations. In the bathroom, I was going to fall with one of her backpacks and one of them told me "Do not go down, why do you throw my food and you're going to pay for it?" so much I bothered, but my failure in the gym class that I started to cry, I only thought of you friends, and although I talk to the counselor does not happen that I send them a notice to their homes and then they bother me again. What I can do?