Good luck to you, man. I appreciate what you are going through. I've not had excruciating pain in quite a while. What I do deal with is an undercurrent of pain that is constant. That said, I can easily deal with it because I tune it out. I've been lucky most of my life but time is catching up to me now and I'm feeling the effects of not taking care of my body over the years.
On a great note, I just got my email from my LBS with the serial number of my new bike that just went into production. This is going to be my Christmas present for sure now.