Nuclear stress test aren't that reliable sometimes. If I were you I would rule out Gerd, so that you can tell if the pain is due to heart disase/CAD or Gerd. If you keep having what you may think is Gerd, you could end up having a heart attack. I have never heard of indigestion causing anyone to break out into a cold sweat and getting very pale and clammy, nor have I ever heard of heart burn causing pain in the jaw. All these signs are symptoms due to cororary artery disease/heart attack warnings.
Try to stop the "so called indigestion" by taking the best otc meds for indigestion, or see your doctor and ask for "the purple pill type med". If you continue to have pain like indigestion then it could be something else much more serious.
I have a friend whose SIL just passed a nuclear stress test. She continued to have chest pain and other symptoms. The doctor agreed to a cath. Before the cath could be performed, she had a very bad heart attack and emergency bypass x 5. I think she is 42 years old.
Good luck and don't wait around too long. If you think you are having a heart attack, chew up 2 adult aspirins (I know, yuck) and call 911! It is better to be safe than sorry. If you were to have fast acting nitroglycerin, use it, of course! Some PCPs will give anyone a prescription for the nitro if the patient feels they need it, due to undiagnosed chest pain. It's good stuff to have around for us cardiac cripples, lol :)