Thanks for your question on Health Care Magic. 
I can understand your concern. 
Since your extensive cardiac and Pulmonary work up is normal, no need to worry for major disease. 
In my opinion, you are mostly having 
stress related 
chest pain. 
Stress is the biggest risk factor for GERD (
gastroesophageal reflux disease). And this can cause central 
chest tightness, pressure and burning chest pain. 
So better to 
consult psychiatrist and get done counseling sessions. 
Try to identify stressor in your life and start working on its solution. 
You may need anxiolytic drugs too. 
So avoid stress and tension, be relax and calm. 
Don't worry, you will be alright. 
Hope I have solved your query. 
Wish you good health. 
Thanks.