Thanks for your question on Health Care Magic. I can understand your situation and problem. Yes, your should definitely trust doctors and reports. If multiple ER visits said that your ecg and blood work up is normal than no need to worry much for major heart and lung related causes. In my opinion, you are mostly having anxiety related symptoms. 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. Quit smoking as soon as possible, as it is not good habit. Don t worry, you will be alright. Avoid stress and tension, be relax and calm. Hope I have solved your query. I will be happy to help you further. Wish you good health. Thanks.