Thanks for your question on Health Care Magic. I can understand your situation and problem. Since your extensive cardiac work up is normal, no need to worry for heart diseases. By your history and description, possibility of stress and anxiety related symptoms is more. So 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. Also quit smoking as soon as possible. Hope I have solved your query. I will be happy to help you further. Wish you good health. Thanks.