Your chest pain may be a condition called Costochondritis. It's an inflammation of the cartilage/soft connective tissue of the ribcage. It can happen in the middle of the chest around the Sternum, and in other areas where the ribs transition from solid bone to flexible cartilage and connective tissue. The inflammation can cause sharp, severe pain. Enough to make you involuntarily wince. It's basically a benign condition, but the pain can be severe, leading some to believe that they are having a heart attack. It is a common problem for many people who live with various autoimmune disorders. Have you ever talked to a Rheumotologist about this symptom?