Suggesting a cleaner doesn't actually help the OP, because the real
problem is her OH's attitude. Men don't need to be told that housework needs doing, or that it's not fair to let their partner do it all, and so on. Well, not ones worth being with, anyway. They are adults; the possession of a penis, or working away from home for several hours a day, does not mean that they are somehow miraculously blinded to mess or things that need doing. Telling a partner that things need doing and it should be done is just taking responsibility for the behaviour of another adult, and no-one should be expected to do that, for any reason.
This has nothing to do with not seeing mess, or being naturally untidy, etc. I like plenty of other adults, female or male, am naturally untidy and hate housework, and I still do it because I respect my partner, I would be ashamed to sit around and let someone else do it for me, knowing that if I won't do anything then they will be forced to do it. Men like this are lazy and sexist - they see housework as beneath them (but not beneath you, as a woman), they know you have to pick up the slack, they are perfectly fine treating you like a servant, etc. And now you have a son who will grow up learning that you are a dogsbody. The refusal to consider a cleaner shows that he quite specifically wants to keep you as essentially a servant, and that it's nothing to do with not seeing or knowing what needs to be done. He wants you to be doing it all.
I saw another thread from you, and you knew then that he's a knob. Why on earth would he change, when he has you exactly where he wants you? Changing offers zero attraction and motivation to him, because it means him having to do stuff he doesn't want to, and which he sees as beneath him, and having to treat you like an equal and a real person, etc. Changing is actually to his detriment, so why would he? And he has a track record of 0% success rate with changing so far.
The most important questions here,OP, are ones about YOU: what are you getting from chasing this hopeless fantasy of being able to change him and make him respect you? What dysfunction from your childhood are you acting out here? Would you not prefer to be with a man that already loves and respects you, doesn't think you're his personal servant and nanny, and who doesn't need changing (or who genuinely would, if needs be)? Now you know he won't change, how much are you prepared to be damaged, and see your child be damaged, by being stuck in such a crappy family dynamic?
Also, YY to everything AF said.