My job is making me depressed. I need some good advise?

I am currently working as a busboy in a low level restaurant. I am 21 years old, yes, I'm still a busboy. Anyway, my boss and the chef consistently downgrade us, they along with the manager talks to us like we are all trash. When were not busy they have us performing some dingy task like scrubbing the walls. I have a lot of confidence that I don't want to lose and I'm thinking about starting a tax business and this job is making me feel to low to do anything. Should I just quit considering I'm only making about 150 a week?