dear Dennis,
I agree with mathew that it sounds as if you nerve has suffered some damage.
It seems that playing the guitar is difficult for you but I would also say that it is most probably the best therapy you can think of.
I have recently been having some success (as in better fine motor performance- not perfect but better) with nerve lesions using elastic therapeutic (Kinesio) tape.

If you tell me where you live I might be able to ask the participants of the courses I have held (on using this tape) in the UK to see if one of them is in your neighbourhood and could help you with this. I am saying this because not everyone that uses this tape is trained to use it in neurological disorders.
If you are interested, please send me your details on my email address and I will get back to you.
[email protected]