I will give you my honest opinion on this whole thing. I once worked at McDonald’s when I was probably in my early 30’s. It was a miserable place to be. You had to stay in long hours on your feet, and put up with a lot of garbage from management and customers. For me it was very emotionally devastating. I didn’t last very long there. In fact, I was fired after three days. I couldn’t keep up with it. Any kind of food business (supermarkets, fast or r), are bound to take a toll on your menta, physical and emotional health after a while. I would tell you what my father used to tell me. If you don’t like the job, get another one first, then leave. But make sure you leave on good terms. Don’t go storming out of there, cursing at your manager. Give them notice and leave peacefully.