william, my favorite college team has a catcher who is listed at 5'9" and 150 #. This is a major div. 1 school, so in order to make the team this kid had to be a standout in high school. Work to be the toughest, smartest, smoothest, and quickest catcher on the team and you'll make it.
BTW, my son is a catcher, and is one of the smallest kids on our team (14U). Last year a former high school coach was watching our game and told my son he's the best catcher he's ever seen.

It doesn't take physical size to play the position, you just gotta know what you're doing and be dedicated enough to work at it.