That sucks. Personally, I would try to just do less, without asking. On call? Don't answer. They probably won't fire you if they're running like that because there will be no way to replace you. And if they do fire you, oh well, you were planning on quitting that job anyway. I would spend most of my time at that place applying to greener pastures. Interview during lunch, come back like an hour late, just tell them car trouble or something. There's no reason not to lie to people that abuse you.