Well, thanks for the advice. I stopped procrastinating and saw a doctor who, although couldn't provide any immediate solution, gave me a little comfort. I have evedently hyper-extended the ulna, one of several nerves extending into the hand. A test revealed that this nerve wasn't severed and most likely not being pinched by swelling, therefore surgery or steroid injections would not be necessary. His best advice was to give it time to heal (evidently slower for nerves than bones or skin), alternate hot and cold packs, and to keep the hand as still as possible. No guitar.
One thing I was glad to learn is that carpal-tunnel syndrome evidently affects the thumb and or first three fingers, due to a different set of nerves that run an alternate course through the arm. So this, I think, is ruled out.
So, we'll see how it goes. I'm hoping to regain feeling in the hand soon, and that this won't last for too long. Might be a good opportunity to learn the kick-drum or kazoo