Sorry to hear about your back Doc! I did something similar when we remodeled our house. I was pulling a nail out of the concret and felt an intense sharp pain in my back. When I felt it, I hit the ground in sever pain. Had to have help getting up and was in pain for about 50-60 days. It eventually went away. But it sounds like your's might be pretty bad.
I hope all is well with you and the family other than your back issue.