Have you tried antacids when you're having chest pains? If they help, it will let you know the pain could be related to GERD or high stomach acid. That causes awful, stabbing chest pain. My pain would radiate to my jaw, so I went to the ER several times certain I was having a heart attack.

Also, gallbladder problems can cause pain in the middle of the chest, and can cause pain all the way into your back and shoulder pain.

If there is absolutely, nothing physically wrong with you, you might need to consider medication. I take 10 mg of Prozac and it pretty much prevents panic attacks.