Should I quit my job? It is depressing me.?

I'm 18 years old, have a wonderful girlfriend, a car that works great, I live at home, and don't have to pay rent with a supportive family, and I have a 40 hour week job, in the lumber yard at our local hardware store. I plan on working here for another year, then going to school. However, my job is horrid. My boss is always stressed out and angry, and every time he is around me, my blood pressure skyrockets. I only get paid minimum wage, I can't run the forklift cause I'm not 21 and therefore I have to do all the dirty work. like sweeping and picking up garbage. The guy I work with the most has not picked up a broom for the entire 3 months I work there. Once the yard manager leaves, he gets on the forklift and moves lumber piles around all night, leaving me to deal with all the customers and clean up. I get sick at the thought of going to work, and I seem to be depressed and down all of the time. But my parents just think that I want to quit because I'm lazy which is not true at all. I want to quit but I don't know if it's the right plan.