Robert,
You poor thing!
My brother was bitten by a brown recluse when he was a child, although I think it was caught sooner so he didn't have to be admitted or undergo surgery (yikes!) You have my heartfelt wishes on a speedy and uneventful recovery... and on Christmas Eve/Day... ugh! I spent one Thanksgiving in an ER, and it's never a pleasant thing (well, I guess it would be if it was for the birth of a kiddo, but that's about it!)
Here's a link for everyone to inform themselves about these nasty critters, including a photo showing the characteristic violin pattern on their back (hence their nickname, the "fiddleback spider" --
Brown recluse spider - Wikipedia, the free encyclopedia