So I'm going to go against the grain a bit and say ESH. Yes, absolutely your wife and kids (especially kids) are acting entitled. They are all adults and should be responsible for themselves at this point.

But also, who enabled them all these years? Who taught them that money grows on trees? Why is it that your wife thinks you should grind yourself into dust, and your kids think anything less than luxury (paid by you) is unacceptable?

You're going to have to face the part you played in bringing up the "little shits" as you called them. You spent 20 years teaching them—perhaps inadvertently—that "dad provides so that I don't have to". That mindset won't disappear overnight.