My back has never been the same since a car accident...?

The accident was two to three years ago and when I started seeing a doctor they told me that I had swelling around my spinal cord. Sometimes I experience pain in my back and it usually is up the middle of my back if I sleep wrong or physically do too much. I did physical therapy for about four months after the accident but don't any more. Is there any way to stop the pain completely...please, preferably answers from people who know what they are talkin' about.