Your H is a slovenly pig. He treats you like a maid and your home like a hotel. Although people who stay in hotels and treat housekeeping respectfully, do not leave all their shit everywhere expecting housekeeping to clean up after them.
This is not about organising toys into certain boxes, this is doing one's fair share in a household and picking up after oneself. The fact that he won't even wipe up spills he has made or put stuff in the dishwasher. What a pig. How can you be attracted to that? Is this how you want to spend your life? I don't know what age you are but if he couldn't give a shit now, he's not going to be any different in 10/20/30/40/50 years. It's also setting a terrible example to your DC.
If you must, you have it out with him one last time before pressing the nuclear button. Each time he leaves his shit everywhere, tell him to pick it up. Every single time. Stop doing anything for him, no more laundry, no more cooking, nothing. Zero. If he doesn't change, divorce him.
If all he is doing is contributing financially, but then creates a ton of work for you because you are cleaning up after him, then divorce him. He will then be contributing financially but you will no longer have the mess to deal with. Win win. And when people ask why you divorced, you can tell them that he was a disgusting messy pig who expected his wife to pick up after him.
But honestly, I doubt he will change. It will get worse once you have a newborn because you will be recovering from birth and have a toddler and have that horrible manchild turning your home into a pigsty.
He may think you can solve all problems with money, but you can't solve his attitude - he seems to think that he doesn't have to pick up after himself. Unless you plan on having a housekeeper in 24/7 then he will still not do his fair share and you will be looking at piles of laundry, the bath not being emptied (which is a massive safety risk for toddlers and babies), dishes and cups scattered everywhere, etc.
I think I read on here before a phrase - every time he doesn't tidy up after himself, it is like saying a big fuck you to the wife (because he doesn't care about the impact on you). I think it was in that thread that I first saw that article about the husband who said his wife left him because he left the dishes in the sink.
Look back at when he was away for work - you said it was lovely, the house was so tidy. That could be your life, and he'll still have to financially support you, so LTB. He doesn't respect you.
What would happen if at the weekend you said to him - no you're not going to golf, no you're not going for a nap, no you can't go see friends because you have housework that you need to do? That has to be done first. And stop saying it's him helping you, it is him needing to do his fair share.
I'd also consider that if he continues leaving his clothes all over the floor that you bag them up and put them in the bin yourself.