I'm sorry Gotit, I so empathise with you, My situation is similar, it's not my H's fault, of course I understand, but I have unwittingly become the sacrificial lamb. I am now responsible for every single thought and action in this home, while for example, DH sleeps away the afternoon in the sitting room.
My H was selfish & emotionally unapproachable before this health issue, so I know he will not be amenable to being asked to go & have his siesta in his bedroom... leaving me/us to get on with being "healthy & normal" , able to speak on the phone without being listened in to, or just allowed to be something other than support animal, servant, helper.
When I talk to my friends they say I need to see a Psy. To which I reply I am not depressed, I am implicitly lucid, & I know this is my life now unless I choose to leave.
I'm told the therapy will help me accept & show me ways how to deal with it. (I doubt it)
Others say, "Throw money at it" (the problem), in your case it could be buy a 2nd chair, or somehow build a room onto your house, so that he could be comfortable in his office, but near the family. & get in help, this could include covering time for you to have respite.
But It seems your real issue is that he has switched off (mine has too but he had a massive Stroke, so you can no longer ask, beg, expect change) from normal family interactions & has possibly taken refuge in his work to prove he is still of value. it sounds like his health has given him a Joker to opt out of any family responsibility and interaction, & doesn't see or care that the elephant in the room is his constant presence/non presence
I know how shit it is, I wish I could offer a solution. What I do know nearly 4 years on, is that if I was younger I would eventually have left, It is slowly destroying me. It is not a life, there are only so many sacrifices that you can make. & my H incapable of recognition. it's thankless, It's endless.
Clearly it is too early for you as there is a possibility of improvement. & your DC are young.
But however hard it is, I think you need to tell him, without conflict, where you are at, what problems have fallen in to your lap too, & discuss what can be done to alleviate them before you arrive at crisis point.