waking up with stiff fingers for ages now . what could this be

It could well be to do with your diabetes, take a read of the following from the Mayo Clinic:

http://www.mayoclinic.org/diseases-conditions/diabetes/in-depth/diabetes/art-20049314

I get it in my fingers sometimes, during the day but mostly in my toes at night. It is some sort of cramp. Drinking more water helped me a lot but, now that I stopped taking statins, I don't seem to get them anymore. Nothing to do with high bloods though, they're pretty good.

I used to have this, on and off for a couple of years. I would wake up and my hands would be straight, stiff and with a deep internal ache (sometimes quite mild), particularly across the knuckles at the base of the fingers. They ached worse in the cold.

It all disappeared when I gave up wheat and lowered my carbs drastically. I was never tested, but suspect it was diet triggered rheumatoid arthritis.

15 years later it has never come back.

Patrick Holford has written a book about it called Say No To Arthritis - might be worth a look.