How to treat my upper back pain?

Hi doctor,

While sitting on a sofa, I was completely relaxed, and my body was lying unbalanced against it. Suddenly, I felt some pain that started in the upper back area. But it did not disappear even after I got up and did a lot of body straightening and stretching. It was minor. Particularly in the night, I slept with difficulty. In the morning, I did a bit of exercise, jogging and relaxing. But it remained. Next night I felt severe pain in the upper back. I was unable to sleep. When I slept flat, I also had the same pain. Turning to either side, there is a slight comfort. I never had this problem before, especially when I am lying flat. When I am sitting normally, almost in the middle of the back, center area, a minor pain is present. Please suggest.