To R, the WS must change, but R is not necessary. D can be the best way to heal after d-day. More important, you can't make your WS change - but you can ask for the changes you want.
You can also set requirements, as in 'If you, WS, continue to do/not do ____, I will choose D.' If your MC won't support that, you definitely need a new MC.
That's one of the reasons IC is pretty much necessary after d-day. MCs treat the M, but the M didn't fail. ICs treat the person insofar as the person wants to change. Does you H want to change? My guess is that he doesn't, but that would leave you in an M you don't like.
If you can't set requirements, a good IC can help you. That might cause you to end your M, but I think you and your kids will probably be better off if you're not carrying around the weight of being in an M you are unhappy in.
My reco is to require what you require and ask for what you want but don't require. There are a lot of things my W & I do that the other doesn't like, we we tolerate those things. I didn't tolerate much bullshit over her A - and our MC didn't, either.
*****
IMO, R has to be between equals. You both have to be able and willing to raise issues. You both have to be willing to work to resolve issues. You both have to give enough of what the other want to make the other want to stick around and keep giving.
For example, my W has to accept my long bike rides. I have to accept that she has her hobbies that take time away from me. If we had young kids, I'd have to participate - and I would hope she wouldn't tolerate my texting her, except in an emergency, during her chorus practices and her rehearsals.
You seem to be accepting more responsibility for child care than you're happy with. That's a big issue between you and your H. You're unhappy with the time he takes away from home. That's a big issue.
R is a process of building an M that serves you both. How does your M serve you? Is that really enough for you?
*****
I do my best in R not to take any crap from my W; she does her best not to give me any. I do my best in R not to give any crap to my W; she does her best not to take any. If we've done that right - if we haven't suppressed any anger - I won't JFO again. If we have unwittingly suppressed anger, maybe I will be, or maybe my W and I will become madhatters.
I think we'll be OK because I believe we address the issues between us. No rug-sweeping about much of anything.
You're accepting a subordinate position in your M. That would be OK if that's what you want, but you don't.
For your sake, please raise these issues now. Set your requirements. Ask for what you want. Walk away if your H won't step up to create an M that serves you both well.
True, you can't expect your H to change. It's also true that he can't expect you to stick around if he doesn't.