Hello Juders, I'm so sorry you have had to add your dismay at the appearance of your hands to the burden of T2 diabetes. The person who said you had the hands of an 80-year-old was spiteful/malevolent/ totally tactless and incapable of empathy. (I don't care if it was your mother, that would just make her guilt worse!) Personally, I prefer skinny hands that show bones to plump ones. Just as well, as I am an under-weight 82-year old. What I don't much like is the great fat worms of veins that stand out on the backs of my hands & wrists. I used to dislike my brown sun/grave spots, but miraculously they seem to have faded away! I wish I knew what I did right. I suspect it was staying out of the bright sun, or just staying indoors more. The latter of course is not a good policy, for many other reasons.
I recently acquired some stretch bead bracelets, which I love. I didn't want to wear them and call attention to my enlarged veins. I have found a solution - ice silk fingerless mitts. They are very light, designed to protect from UV light. They do look a bit Miss Marple, but I will be glad if they stop the grave spots from coming back and I now feel I can wear my lovely bracelets with them without drawing attention to my ugliest feature.
Imo it is not possible to plump up bony hands except, perhaps, by gaining fat or/ heaven forbid, retaining fluid. For skin dryness, I am currently enjoying Batana Oil. It is primarily marketed for hair, but skin also gets a mention. Despite being called an oil, it is more of an ointment. Its texture resembles that of crystallised honey. Warning - it has a strange smell. In its favour, it contains no added chemicals.
Good luck!