There are a few things that I have done to help recovery from my back pain. Granted, I did not suffer an accident like you did. My back pain came on sort of gradually and not from one specific event. I did a lot of physical therapy and chiropractic but this only helped me in the short term. One thing that I think has helped a lot is called Alexander technique. Usually people use this for posture so for me it has been great because I slouch a lot and this led to more pain. I have also been doing some yoga exercises and multifidus exercises that I learned from an ebook I bought online. Not sure if I can post the link but I got it here: www.eliminateyourbackpain.net. It has great illustrations and step-by-step instructions that have been helpful.
Losing weight (about 10 lbs.) has also seen to make a big difference for me. I had a little gut before that is almost gone now and it seems to have taken a lot of pressure off my back.
Best wishes!