Excuse my French, SM, but he's quite the little mindfker isn't he? Suddenly he's refocused the discussions on the house and how he isn't happy. No doubt further probing would reveal the reason he isn't happy with the house is because you have failed to keep it pristine to the point of sterile, all your fault, etc. etc.
Incidentally, if you haven't read it, Ruby Wax's autobiography How Do You Want Me? might make compelling reading, her parents were abusive and doolally about neatness to the point of obsession as well.
He isn't happy because you are miserable. Which translates as, he's not happy because you are now standing up to him instead of cowering in a corner and agreeing with everything he says. I forsee his unhappiness increasing as time goes on. How can you change that? Well, it depends. Do you want to make him happy, or do you want to make yourself happy? If the former, you should go back to the way things were. If the latter, you should leave him. Sorry to put it so bluntly, that's only my view of course.
But more the point, how do you make your children happy? I feel this man has blighted their existence, and made them afraid to be children, much as he has made you afraid to be anything other than some 1950s stereotype of a wife he has learnt from his parents. I bet in 1950s stereotype land, children were pristine at all times and never made a mess anywhere either.
As you say, you're not happy, he's not happy, but you can choose a better future.