It's not very good to not be able to sleep in your bed.
There a pain killers that are available, other people on the forum have talked about them, though it seems to take some persuading to get the doctor to prescribe them. You have to go and see them more than once, I think.
Apart from that, can you lower your feet in bed, seeing as that seems to help in the armchair?
The other thing is, can you improve your blood sugar control? so that can at least stabilise, and not have any further damage, and ideally have an improvement.
If you can increase the anti-oxidants in your diet, especially in fruit and veg, without raising blood sugars, that should help.
Also people say that Alpha liphoic acid is good, that's also an anti oxidant, but not so widely available in foods.
Also a vitamin c supplement might be good, as people with diabetes often have a deficiency because we use so much of it fighting the oxidative stress from high blood sugars.
I think it's important both to find something that reduces the pain for now, and also to take a positive view that you can improve it, or reverse it. You have, after all, reached a very fine age, so you have been doing some things right, so you can do more.