I'm not sure what's making you unhappy. If the teacher is teaching methods other than what you have been doing, there's no reason to not keep doing it your way after the class is over. Sometimes though in a class there is an "aha" moment when I realize there's a much easier or better way to do something. You paid good money to take the class, so you might as well finish it to see if there's anything of value to you. On the other hand if the teacher or the other students are what's making you unhappy, life is too short to be miserable.