Not wanting sex

How do you ladies deal with the constant pressure of keeping your SO satisfied? I’m a stay at home mom of a 2 year old and 27 weeks pregnant with our second. I’m a full time student, I work nights and weekends, I run a small business from my home, and I take care of every last detail around the house. To say I’m exhausted is an understatement. Anyway, my husband seems to think that keeping him satisfied is my job and now sex seems like another chore. How is it that I’m responsible for so much already and now I’m responsible for his pleasure? I should have sex because I want to, not because “it’s my job” or just to keep him happy. All my husband does is pay our bills which of course I’m grateful for, but that’s doesn’t diminish the 2,000 other things I constantly have to tackle alone while he’s working. Anyone in the same boat? Any tips? If you’re going to be rude just don’t comment.