What Causes Pain Throughout Left Side Of The Upper Body?

Hi. I am 20 years old and significantly overweight. (260 lbs 5 10 ) recently I have been experiencing pain throughout the left side of my upper body, throughout my arm, neck, and chest. I am concerned that this may be heart related and have already been to the ER. The only tests they performed were an EKG and Troponin test, but I realize that may not rule out angina. I was discharged with a diagnosis of anxiety and told the pain was psychosomatic, though it has persisted for the past two weeks. I am very worried and have been taking aspirin quite frequently, as well as having completely changed my diet. The pain comes on at rest and varies between burning, throbbing, stabbing, to dull and tight and squeezing. What do you think might be the cause?