severe back pain

So the debilitating pain is becoming more frequent. I'm 33 now and have been peddaling since I was 16. I grew up in the rocky hills of Santa Barbara and rode all up and down the coast, if you're not familiar just imagine some of the toughest terain you've ridden. I have opted to stick with a hardtail this whole time and have incurred some fairly serious injuries over the years, a few which put me in the hospital.
I moved to Austin last year in about the best shape of my life and stopped ridding seriously for the last year due to debilitatly back pain. I have not been off road becuase I know I can't do it anymore. And as an example this last Sunday I rode for only 30 miles on my mountain bike, on road, threw in some sprints and now again I have not been able to walk for the last four days. The lower back pain can leave my on the coach for as much as two weeks.
I've seen a chiropracter, massage, and did acupuncture yesterday and none of these practices are helping me. I don't know what to do.