Oh man. This is one I can relate to.
For me, the beginning of it all was a summer digging drainage ditches around the property, and filling them with 14 tons of 3/4 inch drain rock. One shovel full was not bad, and 14 tons worth one shovel at a time was not bad, but the action of having to jab the shovel into the existing pile of gravel with sufficient force to overcome the resistance that comes with a pile of gravel that big ... bulging disc L4/L5 putting pressure on the sciatic nerve ... OUCH.
I didn't know pain like that existed. Actually called 911 on myself and had two shots of morphine in my ass to ease me back. Luckily we have cork floors and I could drag myself (literally) to the bathroom. Slept (sort of) on the living room floor. 6 oxycontin a day--and an appreciation of what chronic pain can do to you, and the dark thoughts that start to materialize. I was good for 2 hours, and then stared at the clock for two until I could take the next one. Wow.
But, with perseverance, dedication to a physio routine, building up core muscle strength, and lifestyle changes (lose weight) things got better and I was able to return to the realm of education. Without being legally stoned.
The problem still persists, but I have learned to listen to my back, and if I start feeling things in my left knee, it is time for some stretches and sleeping with a pillow under the knees. So far, that does the trick.
One thing that was very helpful was classes with a friend who is a teacher of the 'Alexander' technique:
http://en.wikipedia.org/wiki/Alexander_techniqueI had no idea how many bad habits I had--simple things like how to sit in a chair without putting undue pressure on one's back and that sort of thing. Fascinating what we don't notice.
Take care. It will take time, but there are incremental improvements along the way that one can celebrate.
Cheers
Ross