Your symptom similar with me. It is anxiety. Dont worry buddy. You are fine.
Please stay away from medical and symptom checker website. Your anxiety will become worst if you keep digging for symptom that you had.
Your symptoms is not related to serious illness like geart disease,cance etc.
For your information, i've ran to ER as much as you do. I thought i got heart attack but after the test, my result was normal. Im healthy. After that, i ignore all the symptom that i had. Instead of digging my symptom in internet, i seek medical proffesional directly.
Anxiety can have many health problems associated with it. You may be suffering from something like generalized anxiety disorder, panic disorder, or social anxiety. You could also have overactive adrenal glands. I suggest you see a doctor about it. Diet can also play a role in it. You might have a vitamin or mineral deficiency. Ask your doctor for a blood test to see and then adjust your diet if you do have deficiencies. Some foods are known to promote relaxation and relieve anxiety. I will post 2 website links to help you. This first site is the physical effects of worrying. It has very useful pieces of information http://www.webmd.com/balance/guide/how-worrying-affects-your-body
The second link is remedies that reduce anxiety
http://www.health.com/health/gallery/0,,20669377,00.html