Hello,
From your diagnosis, you could be suffering from scoliosis.
Scoliosis is lateral displacement of vertebra, though it's not very evident until deviation is too much. It usually occurs in thoraco lumbar region commonly. It could be due to trauma or in few its adolescent type, where you would have developed during adolescence but if you were healthy and fit physically your back muscles were strong you would have not realized or ever had the pain. It's a possibility that off late you were under stress and lost weight that now it's evident now.
The best treatment for scoliosis is to exercise and tone your back muscles. Vertebra or back bone is what produces posture and strengthen your back. Strengthen your back will help you and relieve you of pain.
Take Tylenol for pain. If pain is still too much visit orthopaedician.
Thank you.