Welcome! I'm glad you started your own thread. I hope you get a lot of replies.
I get tachycardia, maybe not quite the same thing as afib, but it gets going at 165 beats a minute regular, and sometimes I can't get it stopped with metoprolol or atenolol or Valsalva maneuvers. After a few hours I have to go to the ER and get the rhythm converted.
My point is that, in my case, the rapid heartbeat nearly always starts with eating my "trigger foods." I've kept a food log/journal, with the guidance of my allergist, and it's helped me find a list of foods I have to avoid. It's not like a peanut allergy, not something that can be diagnosed with a skin or blood test. It's a matter of eating too large a quantity of the specific foods that cause the reaction.
There are lots of categories of food intolerances/sensitivities. The food log helped me find mine. I happen to be intolerant of any foods containing sulfites, but others have problems with MSG, histamin releasing foods, various preservatives, etc.
It takes at least a couple of months to find out if food intolerances is the problem, but the food log is free and easy.
I was thinking of ablation, but I don't even need atenolol as long as I avoid the foods I don't tolerate.