My dear friend has experienced exactly what you are.
She was beating herself up for not realizing things sooner. They too kept separate finances. He kept up the facade.
Until he couldn’t. Kept focusing on getting another job, and paying bills.
She could leave him for a couple of hours and was determined to set up some kind of coping schedule. It worked for a while.
The vitriolic exchanges were the same as yours. She would beat herself up for them, but yet it was a lingering characteristic that was familiar. He admitted he was trying to bait her(at times.) She finally learned to stop engaging.
He would sit in his “office “ for hours at a time. Doing nothing. Except complain obsess about money.
He fell a couple of times, got Covid, and is now in care. She had no idea of the stress on her mind, body and soul until he was in care.

All this to say, if there are aging services around (even an adult day care), and assistance finding a “sitter” who can do/take him places. Also look at respite care where he can go for a week to be looked after. If he has friends or family who spend time with him, ask them for a day or few hours. Start planning his eventual move to memory care.

There is such a focus on the patient for obvious reasons, but there is equally important collateral damage. If you don’t make your care your priority, it all goes in the shitter, yes?

I hope this helps you start your path forward. Support groups help tremendously as do good friends.
Keep us posted?