If you make friends with all the teachers and ask for more work then maybe you can be fulfilled by academic achievement not food, not friendship, and not sweets you can melt away in. Being an actor (in life, not theatre) is like watching yourself bleed through a white shirt, something you can do nothing about as it all spills out. Academic achievement is for those who don't want to become good friends with few people (they don't want to be closely associated with anyone) so they become friends and are nice to everyone because if you know everyone and everyone likes you they clearly don't know you well. If you strive for good grades you have a goal in life and can keep acting, if you don't then you have absolutely nothing.
Hope that cleared some things up :)