What kind of an 'episode' are we talking about? If it's a tachyarrhythmia, formally diagnosed, you are probably on a rate control medicine, and maybe also on an anti-arrhythmic drug? Certainly you'd be on a direct-acting oral anti-coagulant??!? (DOAC)
I have been treated for atrial fibrillation, and can sympathize because I was quite symptomatic, and became deeply anxious over time. Fortunately, mine only came on during waking hours, and for some very odd reason, my heart would calm right down at night and I got good quality sleep...which really helped to boost me during the less-than-fun days. Many AF sufferers find that theirs starts up within minutes of lying down, whether for a nap or for a night's sleep. I can't imagine......what that would be like.
It would help to know what your 'episode's are, a formal diagnosis (if you are comfortable telling us what it is here). If it's AF, it is not a death sentence; it's not going to kill you. If you let it go on and on for weeks and months, unchecked, it can lead to subsequent problems, but the worst of AF, especially early in your history with it, is just a pain where the sun don't shine. With some mental gymnastics, a lot of reading and sharing, you can control some of your fear and just accept that, until you get to an electrophysiologist for some mechanical remedy, this will come and go.
The other thing is that most AF sufferers accept that some activities or states (including mood and anxiety) can launch an episode of AF. We call them triggers: They can be: sugar, coughing, sneezing, belching, straining during lifting, straining during a bowel movement, bending over to tie shoes or to pick weeds, too much calcium in the diet, too little magnesium and/or potassium in one's diet, too much caffeine, other prescribed drugs...the list is lengthy. You might soon learn what sets you off, and from then you can just avoid it.