I remember reading a story about a father coming into school to complain to his child's sex ed teacher. She was telling him crazy stuff like masturbation will cause your penis to shrink. The father obviously isn't happy but the conversation strikes him with a curse.
From then on the story revolves around the struggle he has to not masturbate as his cock shrinks and his life changes around him to fit his new... habit.
Would love to find this story again