First, what exactly is wrong with your back and why can nothing be done for it and who told you this? Because I would get a second opinion real quick if someone told me that. Almost 90% of the time there is something that can be done, whether it is surgery to fix the problem, injections to alleviate the pain and reduce swelling, burning of the nerves, etc. There is a lot more that can be tried then just pain medication. Some of those other things even work better AND longer so who knows. Talk to your doctor and ask what else can be done because he might just be waiting for you to ask that question, you know? Many doctors tend to be more willing to prescribe pain medications when they are used in conjunction with other therapies. Good luck to you.
I had been on morphine and oxycontin, and various other narcotics for about 15 years. I had a C-spine and a L-spine fusion, which helped, but I still needed pain medications. I decided to have the Medtronic Intrathecal Pain Pump implanted, which was an outpatient procedure. I go to pain management every 8 weeks to have it refilled with fentanyl and clonidine. I have absolutely no more pain in my spine. It is the best decision that I have ever made, no more pills, and no more groggy feelings.