In addition to some other medical issues, I too have scoliosis, though in a different area. You mentioned the sacral and lumbar area, whereas mine is in the cervical-thoracic.
Nevertheless, I want to share my experiences. I'm in my mid 40's and never had any pain from my scoliosis until my later 30's. The scoliosis is fairly mild and I hardly gave it a thought.
But then from routine work around the house, I started to experience pain in my upper back and shooting down my left arm. The pain persisted for a few months until I finally went to see a doctor. He looked at the x-rays and said -- his words -- that I "have the back of a 70-year-old". That is, spurs, disk degeneration etc..
A few months later, I went for an MRI which confirmed what was obvious given the pain -- narrowed neuroforamen, etc..
I have tried quite a bit of PT and chiropracty. Heat, Ice, massage, etc. all help briefly but often the pain is back 30 minutes later. One PT gave me great exercises for my hip problems (from an accident), but I've not found any useful exercises for scolosis. There is, however, a PT method for scoliosis I recently read about "scroth": http://www.schrothmethod.com/ But I couldn't find any local practitioners. It also looks too good to be true.
So, I use Ultram ER 300mg, which has been helpful until lately. For breakthrough, hydrocodone or oxycodone.
Usually, scoliosis pain gets worse with age as the disks continue to degenerate and the nerves face greater impingement.
So, if you haven't seen a doc. who specializes in scoliosis yet, I suggest you see one and discuss your situation. But also, as others have noted, a pain management doctor is quite appropriate. GP's are typically not going to prescribe adequately for chronic pain. They also don't have the expertise. You might have to explore various time-release and break-through combos based upon what side effects you encounter.
Regarding surgery, let me suggest that you be very cautious. Aside from injections, I've not had any surgery on my spine and would only risk it if the pain gets so bad that I'm not able to keep working otherwise (and I thankfully have a job where I can work from home most days). You might want to visit scoliosis.org and look around for discussions of further medical options.
When you talk with your GP to ask for a referral, you may want to bring up the long-term degenerative nature of scoliosis and that you'll need a doctor to address issues of long-term pain management.
Sorry if this is a bit of a ramble -- it has been a bad day.
C4-T4 Scoliosis (disk degeneration, stenosis, narrowed neuroforamen, bone spurs)
RT hip and SI joint damage from car accident
Current meds: Ultram ER 300mg daily, breakthrough - hydrocodone 10-15mg, or oxycodone 5-7.5mg. .5mg ativan as needed for sleep.