Help with cantering, I cant keep my butt in the saddle. and sometimes the horse I ride (Santana) I think I make him go to face then he starts hopping around and it scars me because I think he's going to buck even though I know he wont because then my riding instructor wouldn't have me ride him. I really need to learn the canter so I can move on and get into shows

what kind of help?

I really need help