Man I hear you...I also hate what is happening to me as I'm aging. When I was 18 and real stupid with a motorcycle, I had a serious accident (my bike dropped doing about 90KM (55m) /h, trying to slow and gear down before a corner came up fast). As the bike dropped (thank G there was no curb, or I would have most likely died that night), and as I was sliding and scraping my new bike, helmet and jacket to shit (which I worked hard to buy with my part time student job). The bike drifted forward in front of me and the foot peg's caught the edge of a manhole cover...sending it flipping and spinning into the air, then coming back down landing on the right side of my chest (crushing and cracking a number of my ribs, as well it damaged the frontal cartridge around my ribs, along with some major road rash to boot).
Well after weeks of not being able move while in the hospital, I was released to mend at home. But due to my previous fitness level of triathlon training...most of the accident issues eventually were behind me. Well at least least I though all was OK until 2019. As I didn't know the previous accident damaged a portion of my spine, and as my level of fitness started to drop (I was getting fat...with eating too many evening snacks). That all changed when I was involved doing community volunteering (physical work), I experienced a suddenly hit of being electrocuted (a form of a sciatic nerve event, feeling like being electrocuted with unbelievable amounts of pain, leaving me crippled not being able to move for days or weeks). This started my journey of it frequently happening over those three years. But with surgery, physio and then real slow and steady conditioning...I'm out and about walking, running and maintaining a level of training, trying to keep me out that damn chair...(and now I'm almost 60).
I couldn't fathom having to experience the US (Insurance) health care system with dealing my past injury. It would be considered a pre-existing condition, which would be very difficult securing any full coverage plans for my procedure. So I kind of understand how age and what we did in our past to ourselves can suddenly come and affect our health and ultimately affect our quality of life.
Fortunately for me I live in Canada, which has socialized single payer health care, so it's a huge benefit having this type of care so I'm not financially ruined. (I know what I went through is not the same as what your going through, but I understand how health issues can bring a person down. Try to stay strong and find a way to try to remain positive if you can...never give up.)
So I really hope you can eventually find a break, that will allow you to over come some or all your health care obstacles that is in front of you. And your quality of life can greatly improve.
Take care brother, wishing you better health and a better future.
Best Regards.