I see the problem --- heart arryhthmia and anxiety can trigger one another!
Well, the first thing to do will be to isolate the anxiety and learn to get in control of your mind! You can do this by breathing and mental exercises. The
American Heart Association has local chapters that can help link you with heart resources.

I'd suggest that you perhaps seek a teacher of meditation to help you through this time. You really need to be in control of your mind and body, instead of the other way around! What part of the country do you live in? (City, state)?
P.S. My mother has this condition, so I'm also a rather opinionated observer of heart arrythmia.