Well - I don't think it's the practicing, because I've been doing very well for the past 4 years with noticeable improvement year after year. This phenomenon happened bang just one day around the time I started spending long days sanding. That's why I'm figuring there is a link ; it's the only thing that has changed in my basic life.
I didn't mention that this has been all with an electric sander...
The worst of the sanding is done; what's left is detail sanding. I'm sure the playing will come back; the last two days have been better already. It's just that I have a gig in a month, so I'm just hoping it won't take too long to get it back.
I want to thank everyone on this feed for their input and for taking the time to respond.