I don't think your problem is your job; it is your unsupportive spouse.
OK he isn't willing to share the parenting; but he is willing to bring home a paycheck. Since that is what he is offering, you need to take that and put it toward what you need, which is some help with your son and with the housework.
If he has issues with this or gives you the "that's why you work part-time" line, I would say that he works 40 h (or whatever) and you work 30; therefore he should be doing 75% as much domestic work as you are. Since he is doing none, you are hiring out his 75% of the domestic burden.
This is unspeakably sad.
He once said in an argument "no wonder your dad left you when you were a kid...you're such a b-word." I don't think I can ever forgive him for saying something like that. He loves to bring up my dad all the time because I think he realizes he's hit an emotional gold mine that will bring me near or to tears every time.