In India, when someone doesn't feel like working but still has to, one jokingly uses a Hindi phrase which translates to - "I have to do it for the evil-doer stomach" which implies one can't survive without earning livelihood and to earn that, one has to do work. I'm sure there is an English equivalent of this phrase. Does anyone have any idea?
Not quite equivalent but try:
I've got to bring home the bacon.
Unfortunately that will be out of favor in many parts of the world where they don't eat pork, but in the US it means that I have to work so I can feed my family.
How about this? :
I want to quit my job, but I can't, as I have to make both ends meet for my family.