M.M.
First and foremost, I am not a healthcare provider. If you have concerns about your health, you need to seek a proper medical evaluation. Don't mess around.
That being said, I, too have occasional chest pain that is very painful. The first time I became very alarmed and had an urgent cardiac work up. It was determined that I had costochondritis rather than a more serious cardiac issue.
Costochondritis is an inflammation of the junctions where the upper ribs join with the cartilage that holds them to the breastbone or sternum. The condition causes localized chest pain that you can reproduce by pushing on the cartilage in the front of your rib cage. Costochondritis is a relatively harmless condition and usually goes away without treatment. Overall, costochondritis is one of the most common causes of musculoskeletal chest pain. While chest pain can represent heart disease, costochondritis is also considered as a possible diagnosis in adults who have chest pain. The pain can be severe.
I get occasional flare-ups which includes a fair amount of pain and at times, shortness of breath. It lasts about 1-2 weeks. It usually begins after I have exerted myself too much. It's a reminder to slow down and take it easy.