Upper left chest pain and shoulder pain what could be causing it it hurts severely to cough or sneeze?

see below: You describe pleurisy or pericarditis. Sometimes intercostal muscular pain can mimic this. If the pain is worse lying down, improved sitting up/forward, it suggest pericarditis. If you have fever/cough, shortness of breath, it suggests pneumonia with pleural involvement. Were your chest xray and ct done recently/for this illness? A cxr, CBC and echo are usual parts of the evaluation.