Hello, Charliefox --
Don't give up the guitar yet! When I was first diagnosed, I was having trouble playing the piano. My fingers were so uncoordinated that I thought I'd never play anything worthwhile again. But once I got started on the right meds for me, I gradually regained my ability to control my fingers. It is now 13 years since that diagnosis (18 years since my first symptoms), and I am still playing Mozart, Chopin, Schumann, Schubert, and more -- plus some popular music as well. I'm strictly an amateur, but my hands are working!
Good luck with your case of PD. We're all different, but I hope you get careful, appropriate treatment and develop an interest in exercise (crucial!). Best wishes with your guitar-playing, too --