Wow. Getting a spinal tap is no fun. (I probably made myself more nervous than I needed to be, tho.) They had a bit of trouble with me until they moved down one vertebra. After that, everything went pretty smoothly.
I hope you find some answers, Jen, and that they're good ones.
I'm a little surprised, though, to see you say that you expect answers tomorrow. MRIs and spinal taps both usually take a few days to process. With an MRI, you can sometimes get a "cold read" if you ask for it (they get someone to take a quick glance while you're there to let you know if there's something really obvious going on), but it's with the understanding that it's not a binding opinion (he's taking a glance at the films, not making an actual diagnosis).
Anyway... good luck to you. Let us know how it goes!
Paul