My husband is similar to you as he uses a urinal, he keeps it in the dining room as he can't make the stairs. We are going to get a stair-lift fitted so he can at least get back to some sort of normal life and also getting a walk in shower fitted as at the moment he is struggling to lift his leg over to climb into the bath/shower. We have to pay for it all ourselves because we had the sense to curb our spending when we were younger so we had a bit of extra money for our retirement.
My husband says the same as you, how can I blo#### well exercise when I can't blo####### walk, but I tell him that he can't walk because he is sat on his backside all day doing nothing. I am 70 years old and do everything for him, he has been told by so many medical people to walk across the room to build his wasted legs back up again but all he says is 'I can't'. I now tell him that it is his life he is throwing away and if he doesn't help himself no-one else will.
We bought a vibration plate machine and stuck it in the corner of the dining room, I told him to use it for 10 mins. each day and if he didn't he is on his own and I will do nothing for him. He has now used it for a week and says he feels better as the plate vibrates through all his muscles toning them up, but there again, as I said before, we bought it ourselves.
I sat him down a couple of weeks ago and told him to keep quiet whilst I had a talk with him. I told him to think of his lungs as his arms and they are thin and wasted, I said that when you go to a gym and start lifting weights and exercising, your arms start to get firm and muscular, that, I told him is what happens to your lungs, they will get stronger and you will be able to breathe better.
So it is down to you, I don't want you to feel as if I am getting at you, but after living with a husband who moans and groans all day and does sod all, it makes you bitter, because at the end of the day it is your life and you owe it to yourself to do the best you can for yourself. If you cannot walk very far, ask your doctor for a zimmer frame to hold you up when walking, you will improve if you try. You owe it to yourself.