Op, my friend is in a similar situation, her son is severely disabled and she now stays home, the stress of it is enormous, as is her resentment,
what she can’t see is their home atmosphere is always terse and difficult, as he also is dealing with a disabled child, an unhappy wife, and trying to hold down a job to pay for everything, and so he has his own resentments, both can only see it from their side, as when you’re unhappy you tend to focus on that unhappiness and not the other person.
so instead of working together, pulling together, they are pulling apart. Neither seeing the other side, simply giving it lip service due to their own unhappiness.
you need to try to both see it from the other side, two facts are clear.
you need support
he needs to work
so for me unless he changes job, to something non stressful, 9-5 with a short commute, maybe even goes part time, and you both down grade your financial requirements accordingly, then the answer is to hire a carer. One day a week to give you respite. And you leave the house that one day, it doesn’t matter if you get a job, or volunteer, or go hang out someplace, see friends, family, whatever.
or you go back to work full time and hire full time care.
i can honestly say if my friend had at least some respite care weekly I’m fairly sure part of her resentment would ease. And their home would be less of a terse war zone. Even if she went back to work full time or part time and used her full earnings to pay for care, it would be better for them all.
but right now, they are in the trenches, sticking to their decision, and it is hugely clear to everyone it doesn’t work, and her relationship with her disabled child is difficult and lacking in patience, which he tries to counteract with kindness, which is its own problem.
you both need to rethink your decisions.