So what does he say when you point out that being, and continuing to be a husband and a father isn’t all about what he wants you have to put what the children need first, whatever that is. And it’s money and time.
They might be both in school in a few years but school day ends at 3.30pm it’s not like they can commute themselves and come home and make food.
Have you talked about the possibly of your children being ND? Not a certainty but what ifs are good to run through, if they need extra help is he going to be there.
He needs to let go of this selfishness and tunnel vision which I understand is can be more difficult with ND but he is part of two adults who brought two new humans into this world and he needs to start behaving like it. ND or not we as adults and parents have to take responsibility for what we do and yes bringing up kids can be boring, repetitive and difficult, it’s thankless and expensive. But tough titties buttercup that is what you have done.
I would tell him if he wants to remain part of your two adult two kid household that he can do what he likes once xyz is covered, time outside of that (which will be very little)!is his own.
He could do an open university degree whilst kids in school and once they have gone to bed, from the comfort of his household in the time he has available.
But this probably won’t happen - you will effectively be a single parent within a marriage and he will swoop in when he feels like it, you will then feel grateful and he will happily take the praise when people say what nice kids or when they achieve something.
You need to nip this in the bud now, kids need more time outside school hours as they get older, its different, but still they need homework, school admin, uniforms, activities and emotional support with social issues as well as fun family time.
Talk to him seriously- he needs to understand how low down the selfish pecking order he has become.