First of all welcome to the pain management board and please continue to come here for support. I was wondering a couple of things. Did your doctor ever try you on any other meds than Oxycontin? It sounds like alot of your pain is nerve related and usually the opiods/opiates tend not to work very well on nerve pain or if they do usually require high doses. Did you ever try Neurontin, Lyrica, Topomax, amitrypytiline, nortriptyline, or Cymbalta? These are the most commo meds used for nerve pain and somtimes work better than the opiod/opiate medications.
As far as the Suboxone goes, I doubt you get a whole lot of relief from it but I could be wrong. From what most people have said on this board, they get little to no relief from it. I am sure you know that it is still an opiod(buprenorphine) along with an narcotic antagonist(naltrexone). You also can only get it as a sublingual pill here in the U.S. I have heard many people get tired of having to dissolve a pill under their tongue. Be aware that one of the potential side effects of it is actually back pain so if your back pain gets worse after starting it, this may be the culprit. The other most common side effects are disphoria(opposite of euphoria), nausea, vomiting, dizzy, lightheaded. I would really ask to try other medications that specifically target nerve pain.
Now you are correct with the part about getting a "high" off the pain meds because if you are then you are overriding the pain or are in no pain to begin with. I am a recovering addict and I know this all too well and try to teach people the same concept. Good luck and let us know how you do on the Suboxone ok?