Spinal muscles symptoms and conditions

Hi im steve form the UK. I was in a traffice accident in october 2002, i was hit my a car and knock off my Scooter(moped) and landed on my back. I have damged my back tissue and back(spinal) muscles. I have had chronic back pain ever since the accident and my GP has given me Tramadol. I was on them for two years from my accident, then i was off them for one year and now im back on them. These are the only tablets that do help the pain and i have tried other painkillers but did not help with the pain. I get a Dry mouth, (very thirsty), sometimes i itch alot, feel a bit dizzy and tired, when i yawn i tingle all over and my hands and arms go numb. I also feel like im gone into my own little world which is good when im at work as work can be stressful, it helps me calm down too. I take 1 or 2 a day