I make a lot of typos and am constantly correcting myself so I think that just goes with the fibro territory.
I used to have a big problem with my hands. They were very weak, I had problems putting dishes up in the cupboard, etc. I couldn't open jars, or my thumb-latch front door either. My daughter bought me an electric jar opener but I found a jar key at William Sonoma that really worked well and I also have those round, rubber disks that help me open jars. My thumb was soo bad that I could hardly hold a pen and was actually practicing writing with my other hand so I could still pay the bills.
This went on for about a year and then it gradually got better. That's why I feel it was fibro. Still, if I clench my fist and then open my hand, my fingers lock and I have a couple that I have to manually straighten. It's not fun but, in the big scheme of life, it's not big deal! 
I hope your problem will pretty much clear up like mine did.
Sherrine