Numb,

I had several serious of LSB. They are usually done once or week or once every 2 weeks. Mine were every 2. It was minor pain with lots of pressure under slight sedation.
Each shot you should see a little longer and a little longer. If not it is not for you. I started out the same way and after about 12 shots, I only got to 7-10 days.
My Back pain was usually gone within a week, but I am not sure if it is from walking with an exterme gait or the shot, because I still have flairs.

IV pain- there is a cream called "EMLA" that you should ask your doctor for. It is applied prior to the procedure, covered with plastic wrap until your procedure. It is a numbing agent. When I was a nurse in minor surgery, a lot of people said it helped. I have never tried it first hand.
Good luck.
Anita