21 Year Old With Constant Chest Discomfort

I am 21, healthy, 6’2’’ 180 pounds, non smoker, occasional drinker with constant chest discomfort for over 2 years. It feels like my heart is beating forcefully even at rest, with it radiating in my neck and arms, and irregular beats and tightness in the chest. Over this time I have had EKGs, Echocardiogram, chest X-ray, 2 week haltor monitor, chest CT scan, all turned up nothing ( accept a "benign" arythmia"). An electrophysiologist attributed it to “cardiac rhythm awareness”, saying I can simply feel my heart beat more than others. The other doctors thought it was just anxiety. I have been on 40mg Nadolol and now 25 mg Adenelol (beta blockers) which don’t seem to help. There is heart disease in my family but the doctors seem to brush me off becuase of my youth and healthy demeanor. The symptoms are constant almost every day, but do get worse after eating, exercising, and drinking. I don’t know what else to do as it is deteriorating my otherwise great life. Can someone offer help?