Miss,
I can totally relate to you. When my anxiety and worry were at an all time high I had huge palpitations several times a day and my heart would race and pound. The doctors even diagnosed me with SVT then said I didn't have it after an Electrophysiology Study (EP Study). It is extremely scary and causes even more anxiety when you go through something like this and even though my doctor reassured me, I was so sure that something had to be wrong. I finally faced the truth and because of that I think I am getting better. You are fine and you need to realize that you and your anxious thoughts cause the surge of stress hormones to be released, one of which is adrenaline, and this causes your heart to pound and race and palpitate, atleast this is what I've been told. I do alot of breathing exercises, I take magnesium and a multi-vitamin, and I try to remain rational and reassuring in times of panic and stress. This has helped me tremendously and I rarely have palpitations anymore and if I do they are mild amd do not worry me at all. I also found reassurance from my sister who is healthy and who does not suffer from anxiety. She said she has palpitations often and her doctor told her that alot of people have them and most are benign and only worry if she faints with them or gets short of breath. You are young, healthy, the doctors have cleared you of any medical problems so the only thing left to blame it on is anxiety. Anxiety is amazing in its ability to manifest itself in physical symptoms, whether it's heart palpitions, ulcers, numbness/tingling, dizziness, etc. Just rest assured it is anxiety, you will be fine, it is useless to worry about them and once you stop and take control you will find that they will go away. And as for the meds, I was on a beta blocker too and it is just to help reduce the effects of adrenaline on you heart thereby reducing the rapid heart rate and pounding associated with that. Good luck and keep me posted :)