Even having help come every other week to do major cleaning is a tremendous help.

If they're not voluntarily contributing in a meaningful way, then you need to decide what expectations you have and perhaps figure out an appropriate amount of time that needs to be spent in exchange for rent. Help can be had for $10 per hour or less in many places. Even if you want to be generous and give them more than the going rate, figure out what this breaks down to in rent. If either were working it might be a different story, but they shouldn't come and go as they please. How old are they, btw???

My son made sure he checked with me before going on trips and before taking a new job across the country because he knew it would complicate things for me since I was expecting to undergo several surgical procedures. I don't ever want him to feel like he needs to change his life plans for me, and I worked things out, but I appreciate that he cares enough to at least ask!

You do need to learn to adapt as much as possible. Hopefully as new meds are added you'll become more functional... In the meantime, would you be capable of doing more if you had a wheelchair at this point? Would you need mechanical help getting into the wheelchair? (It doesn't mean you have to use it all the time if you're concerned about losing more function.) If your issues are mostly with your lower body, than you need a comfortable set up to do things like meal prep while sitting. If that's impossible, consider Meals on Wheels for yourself. If you can't vacuum, consider a Roomba, etc.

Have you looked into swimming/pt in a warm pool? This might be a big help with increasing your function.

Have you checked to see if there is a ride service for the disabled locally?

You might want to consider buying down into a smaller home with less upkeep and lower taxes. Even if you are approved for SSDI, you'll likely still struggle unless you have other resources. Or, if rents are high in your area, you might consider renting it out and finding a small rental for yourself. --You might want to stay with or near more reliable family...

Rereading your post, how exactly are either of them sacrificing when you say they do very little every day? Are they using your health as an excuse for an extended vacation? While it might make sense for her to be home with you, why isn't he working???