I'm really sorry to hear that you're out from climbing for 8 to 12 weeks. I don't know that I entirely trust chiropractors when it comes to taking care of back injuries. They can't prescribe medications that might be needed, for example. It's probably expensive, but some kind of real doctor who specializes in problems of the spinal cord might be good to consult with.
When you think it might be time to go back, take it really slowly and see how things feel. I had a bad back muscle pull once; thought it was healed up fine, could walk around and bend at the waist no problem, no pain. It was only when I tried to return to work and start lifting stuff like I used to that the pain came back with a vengence.
So my point is that you should do successive approximations of the work you normally do while on your own time, before declaring yourself fit for duty, and then finding out you were completely wrong about it. Especially if you are on workman's comp right now.
I really hope you find a good solution; back problems are a scary thing, because if its not all working right, it can be tough to make a living.
Best wishes.
Tim