Thankfully my DH gets it (though I think he will be incredibly grateful when I'm over it!!!!)
We also have a 4 and a 2 year old, so on nursery days he gets the 2 year old dressed while I shower and have a quick post shower lie-down, he tries to persuade the 4 year old to get dressed, but I take over that if he can't and then I take then down for a pre-nursery banana. DH then brushes their teeth, we both get their coats on etc, DH takes then to nursery, while I go back to bed for 90 minutes, before going into work late...
I do the pick-up, and start the bath/bed routine, DH gets home to help with the remainder, then he cooks tea, brings me the pudding I need to stop me throwing up dinner, then washes up afterwards...
Weekends are obviously different, but he tries to give me some quiet time for a morning nap by getting the kids out of the house (cannot sleep with both kids here as it quickly turns to WW101
I don't have HG, just mainly constant bad nausea, with a few vomiting episodes thrown in here and there... So your DH needs to stop grumbling and accept that fact that you are growing your third child, which is a full time job, on top of everything you have to do!
Good luck!