You don't get addicted to pain killers as such when using them for pain. But you can get tolerance to their effect with continued use. "Stonger" and "weaker" are bad words to use in describing painkillers, as it is very individual. What works in one person doesn't in another, and what causes massive side-effects in someone doesn't cause any problems for another - I no real way of telling which is which. There is alot of information in the medication threads.
Tramadol is classed as a weak opioid similar to codeine. Probably a 50:50 chance whether you will find it better or worse than codeine. ON average however, more people have side-effects with tramadol, including fuzzy heads etc. Taking any weak opioid (codeine or tramadol) at the same time as paracetamol enhances its affect to more than the sum of the individual drugs.
You say you alternate co-codamol and tramadol? Any particular reason? Co-codamol has paracetamol and codiene. It may be best to discuss this with yout GP or Pharmacist, as you may be better with regular paracetamol topped up with either codeine or tramadol for when the pain is bad. Thereby minimizing the side-effects of the weak opioid while maximizing the pain relieving effect. (So would be best for you to find out which out of codiene and tramadol gives you the more pain relief with the less side effects).
There are also NSAIDs which can be added to paracetamol and weak opioids - but these have side-effects and many people can't tolerate. Sometimes low dose anti-depressants are used for their affect at modifying nerve pain and their ability to enhance other pain killers (read the amitriptylline and dosulepin threads). The next stage is then replacing the weak opioid with a strong opioid such as morphine, fentanyl, butrans etc - but this is also a step up in side-effects and needs to be considered carefully.
Hope my waffle makes sense. Have a read through the tramadol thread and the other medication threads, and feel free to send me a PM if you want some extra pharmacist advice (Dosages can't be mentioned with the boards)
I would definitely ask for a referral to one of the specialists for a definite diagnosis. It doesn't mean anything can be done - but knowing that you are fully believed is a great help for your mental state
Also, the physio and OTs at these centres can sometimes be more helpful that local ones that don't really know much. (My local physio gave me core-stability exercises well above what I was capable of - so I was over using superfical muscles and not getting any benifit).
As for DLA - I have chickened out of applying - so I am sure others would be best to advise.