Thanks, GUEST. Someone else suggested the alternating hot/cold treatment to me. I'm going to try it.

I hope your experience turns out to be mine. I could be wrong, of course, but at this point my finger doesn't seem overwhelmingly bad. I'm going to lay off on the playing for a few days and see if there is noticeable improvement. Thank goodness I can still sing! Being in the presence of music is the important thing.