I'm really frustrated about my Dad?

Well...Monday-Friday I work at school..I guess I'm okay with having to do the 5 chores when i come home..but I'm like not even allowed to sit down, I always have to work...and even during the weekends when i go to my grandmas he tells me i'm being "unproductive" and that i'm "too young to relax" (he doesnt want me to have any relaxation time at all). I don't understand this. I can't talk to him about this to him. What should I do?