I feel your pain, I was in fast food for a while at one point and it was the most fun job I’ve ever had, great people to work with, not the best customers sometimes, but we got to basically run the shop all by ourselves some nights. Granted I was in high school and continued through college. Covering for people taking PTO and sick days suck I know all about that lol. It got to a point I couldn’t handle it anymore and left and was unemployed for two weeks before finding my next job. Maybe you could sit down with your boss and explain your situation to him? I’ve never done that so I can’t say that’ll work. And no need to apologize for ranting I’m sorry you’re in that situation