Hi. Thanks for your query. Noted the history and understood your concerns. Since the TMT and ECG are normal the cause is obviously not related to the heart in spite of the pain that you have on left side of chest and back. Hence the most probable cause can be as one of the following: Costochondritis due to stress and anxiety or post-viral infection. Any problem with the muscles of the affected area. Thoracic spine problems. I would advise you the following in such a situation: Get examined by a General Surgeon to get the local pain, tenderness, examination of the back and get the following tests if needed and advised by the Specialist. X-ray of the chest to rule out any problems related to the lungs, pleura and chest wall structure; if any positive findings are present get a confirmatory CT scan of the chest. MRI of the spine in thorax region. Symptomatic management with painkillers with anti-inflammatory medications, oral steroids and further management as needed will help to get you the relief. Please remember that if the problem is due to costochondritis and related to the stress and anxiety, there will chances of recurrence.