Fun - If karate practice is no fun, go somewhere else. If you aren't enjoying that place, go to another place. Keep trying places to train until you find one that seems fun. Don't be limited to the Shotokan system - the system of karate is not important. Just go somewhere that makes you happy.
Life is short, and too much time spent on hard work is poorly spent.
Just do what you want. If your karate classmates are mean to you, complain to the instructor and then quit the club. You don't want mean people punching at you and thinking that you need more humiliation before your character is perfected. Pay for a month, or a quarter, but no more. Be polite and pay attention.