Anxiety Support Group
Anxiety is a physical condition marked by intense and persistent feelings of distress, fear, angst or dread. General anxiety caused by routine day-to-day stresses usually passes quickly and is experienced by almost everyone at one time or another. However, such feelings that linger over time and are very difficult to cope with, and which lack a clear cause, may indicate...

Hope this helps.
I just went out in the heat for a few minutes and thought I was going to die. My h/r was over 100 but came back down. I have MS and the heat is a big enemy of MS. That really made my heart feel bad and my anxiety climb!
I used to take Propranolol when I had palpitations from my thyroid. I need to talk my doctor into allowing them again. They DID help.
Sometimes I think it is because of low blood sugar. Maybe eating some yogurt before sleeping will help.