It's a common misconception among all those who have never had to trudge the weary and relentless treadmill that being at home all day with young children can be, (especially when ill), that just because you are at home and not having to deal with shitty business-related stuff you have it easy.
I have been on both sides of the fence and my position is pretty much on the fence here.
You are knackered and ill. I was a SAHM for five years and I had a lot of health issues which have involved days on end of looking after my children while ill. It is the hardest thing I have ever done, so my sympathies are with you.
However I have recently gone back to work and can now remember how exhausting and draining a day in the office can be. Good days are great, bad days are awful and sometimes it's really hard to shake the day's issues off. When I return home sometimes all I want is peace and space. Of course, that is impossible when children are running wild at home.
So while we all laugh and mock the fifties marriage set-up, it is not completely unreasonable to understand that the WOHM/D wants a calm home to return to.
Of course, we live in the real world, and it is impossible to live that kind of bollocks Utopian dream whereby the (relaxed, happy and rested) SAHP is on hand to offer a home cooked meal, rested babes in pyjamas, a fixed drink and later a good shag.
All I can say is... you're not alone. Looking after children while ill is shit. No one understands how difficult it is until they've had to do so themselves. Not day upon day upon day... But my point is that your dh doesn't understand because he has no idea how fucking hard it is... and for that I think you should forgive him that ignorance! He has after all apologised.
Dh and I are still squabbling like mad and our dds are older than your dcs. It's the age-old argument I'm afraid: who has it tougher. Until you've walked a mile in each other's shoes it's not easy to say who does.