Chronic back and neck pain symptoms and conditions

I was prescribed Ultram for chronic back and neck pain because I had been on Vicodin for a long time but did not want to be on a strong narcotic long-term. Ultram is effective, but i have been on it almost a year and if I run out and don't happen to have any more, after about 12-24 hours I start sweating and I feel weak and can't sleep, plus legs twitch uncontrollably. I guess all pain meds have their problems.