Try a chiropractor. Doctors don't know squat about back problems. I've got back problems, they found my scoliosis at 14 or 15 but said if I was done growing I couldn't ever fix it, I just might be able to help my back not be so tight with so many muscle knots. I stopped growing when I was 12 so i'm stuck with this junk too. Cracking your back feels good now, but I used to do it and now I can hardly move. Also try a deep tissue massage. If you live in a big city it's easier to find a good one. A nicely priced one I had was about 30 dollars for 30 minutes. It hurts while you're getting it done, I won't lie. But that helped me more than anything else ever has. Took away my headaches from my knots in my neck too! Also pressure point therapy that's relatively new I believe, not too many people do it, if you have a nice significant other or good friend, order a book on that off amazon and get someone to try it on you. It's not as good as deep tissue but it definately isn't worthless either!
Best of luck

Willem,
check into information pertaining to chiari malformation. Symptoms fit and they may be able to help you. Piglady