I saw your post just now, but I wasn't sure if you were still checking it. I just wanted to add a few comments.
I've had over 30 nerve blocks. The ones I have had are called paravertebral lumbar injections or nerve blocks. (Mine are for what was acute and now chronic pain stemming from an injury after being diagnosed with a particular condition.) I go to the same pain management center in a local hospital which I like very much.
I did some searching quickly, and it seems that what I've had done and what you are getting done might be similar. It's really not that bad (and if you are afraid of needles, after the IV, I never see the rather large one they use for the procedure as I lay on my stomach, and they go in through my back), and I'm usually only there for up to a couple hours. The next few days involve limited movement for me, but I typically take painkillers which help.
If you would want to talk or have any questions about my experiences, just send me a PM. I hope this helps reassure you!
P.S. - I have also had an epidural before for a surgery, and for me, I'd rather have the nerve block. I did have the epidural for 4 days or so though, so that might be why.
