Did you see a neurologist yet?
This is absolutely necessary. I don't see a psychological reason for your issue. There are neurological conditions that impede the muscle's innervation and control. You will need a brain scan and maybe a lumbal tap to look for inflammatory reasons.
Parkinson's disease, muscle dystrophy, Lyme disease or Motor neurone disease are some of the possible explanations.
I assume that your heart has been checked and your blood works excluded hypothyreosis and kidney failure.
Ok, so the neurological conditions I mentioned above will have to be checked.
You can only find the perfect solultion AFTER the diagnosis. If you have Parkinson's Disease or an inflammation, you will get specific medication. If it's Motor neurone' disease or another condition you can't treat causally, you will need intensive physical therapy. You shuld have that and ergotherapy at this time, anyhow. If you haven't, please ask for it.
The bad thing is that you needed to suffer for 5 years without being checked neurologically! If this had happended earlier, the deterioration of your health could already have been stopped or slowed down.
Get physiotherapy and ergotherapy to gain strength.
Have your Vitamin D checked and get a supplemet, if low.
Treat depression if present as an underlying condition.
Eat healthy food and take vitamin supplements.
Get a neurological examination to find out what causes the muscular weakness and treat it, if possible.
I will be offline for a little while now. If something ist not quite clear, feel free to ask, I will come back and answer until you are satisfied with my help!
If everything is clear now I thank you for a positive rating for my help and wish you the very best.
You are very welcome!