Help. Constant fluttering in chest 3 days now

Hello need someone to talk to. For 3 days now I have discomfort in my chest. Yes I have been to cardiologist and done test 2 years ago and all good. For the pass 3 days I have constant discomfort in chest. Like fluttering and sometimes goes in my throat. I'm scared I'm having a heart attack. Tomorrow I'm going for an echo, stress and getting a holtwr monitor for 3 days. But not sure I can make it through night without freaking out. I went to drs. Always today and she thinks it's my anxiety but will send me for test to calm me down.
Has anyone had discomfort and fluttering for days in there chest from anxiety???