What do i do in this situation.?

First of all, tell your friend that it wasn't your decision to make about which school you attend, that your parents decided. Secondly, you were very stupid to let someone pressure you into sending him a topless picture of yourself. Beware of peer pressure and don't let people influence you to do stupid things that could get you into trouble just because you're looking to be accepted or part of the "cool" crowd.