Why are people so freakin mean to me at school?

I am 13 and in the 8th grade I am really short with red hair and freckles. I hate when Iget picked on! They call me fire crotch because of my hair and call me freckle face bc I have freckles. They asl make dumb jokes because im short. Like they look straight ahead(which is above me) and they say wheres crystal? tryin to me dumb. it gets me down idk what to do?