The palpitations scare you which in turn creates worse palpitations, which then raises your anxiety
.....it's a vicious cycle. Anxiety
feeds off our fears and worry, creating the symptoms you describe. When we get anxious our heart rate automatically rises, so try not to let the palpitations worry you since you have had all the tests, and see if you can calm yourself down. You're not alone, and I think we all try to beat anxiety on our own before realizing that we need help.