Sickness and in health doesn’t really apply here.
If you are married to someone and they become unwell, whether temporarily or permanently, that’s obviously going to change your and their life, depending on the illness it could be significantly and permanently. That’s certainly not a reason for leaving someone.
However, illness (which being ND isn’t, but anyway) isn’t a reason for not doing things you can actually do.
I have a bad back. Doesn’t sound like much. It is, believe me. I’ve spent days in pain, suffering, sometimes silently, sometimes not. However, I get on and I do things.
Part of that is because I’ve no choice in the matter but it’s more than that. If I give in - if I stay in bed because it’s just too painful, then that’s when the decline kicks in and I end up sinking. Anyone who has had an elderly relative go into a home knows how this happen - they retain some independence at home and they force themselves to do some things, go to a home, that’s taken away from them, three months time they are bed bound.
That’s not good for anyone.
It isn’t good for the DH. What do we always say on here, that resentment builds up.
It isn’t good for the children, I don’t care what people say, it isn’t optimal to have one parent detach to this extent.
It isn’t good for the OP. She’s in a vulnerable position, and she is isolating herself further.