I agree with NP as far as the nerve blocks being more painful - when they hit my thoracic nerve in the right spot, I just can't explain it. I jump and start twitching (2 lovely nurses that work with the pm hold me still - not so sure that they're that lovely actually
). It is only with the T8 nerve that was crushed that I respond like that though. He does T7 and T9 on both sides also and they are ok, a little bit sharp but ok. If the nerve isn't too damaged, it shouldn't be too painful.
I have also had a spinal block (around the cord in my upper thoracic) once before my surgery and that wasn't painful - just weird. I don't think that this is what you're having though? I was in the ER because I my diaphragm was spasming because of my thoracic injury and this was how they stopped it so I could breathe properly (they tried some other meds etc first) - I also had to stay in hospital for a while. When I hear epidural block - this is what I think of because that's how we refer to it in Aus. Otherwise it's a nerve block at the root of the nerve.
I think that the other posters described it very well. I'll be thinking of you on the day.