Your daughter sounds like she has extremely severe depression. That is not the same thing as OPs husband is it?
If he can potter around, go to the shops, do some gardening and whatnot, then he can f'ing well go to the gym and force himself to do things he doesn't want to do. It isn't the same as someone being basically catatonic due to severe depression as you've described your daughter being. To literally be too depressed to even get up and go to the toilet is severe.
I do not appreciate being shamed by someone like you, who is by the way heavily biased towards her own experiences, or you shaming op because of the same. Your daughters situation is from what you have described entirely different and I would expect you to have the common sense to know that.
I find it interesting that OPs husband is capable of things when he chooses to be, but not when he doesn't want to be. Does your daughter behave that way? It doesn't sound like it to me.
As a result, given what OP has said in her post, my sympathy towards him is limited, and I'd hope yours would be as well towards your daughter if she were exhibiting the same behaviour. Why? Because fighting a disease is hard in pretty much all cases, there are some who are so heavily burdened that they need help, but there are some who need to muster the strength because it is demonstrably shown to be there - as is the case with both myself and OPs husband.
There are many times I don't want to go to the gym because I feel down, but is that a good enough reason not to? Sometimes yes, but most of the time actually no. If I want to beat this thing then I need to get uncomfortable sometimes. The same is true of OPs husband because he's dragging everyone else down with him, not least the very woman who is going out, working and paying the bills while he sits at home doing a bit of weeding every now and then.
If your daughter is out there weeding rather than lying in bed absolutely incapacitated by depression then you need to get a grip, but if she genuinely is that bad then my heart goes out to you, and again, that situation is entirely different. Have some perspective.