Arrhythmias Support Group
Cardiac arrhythmia is a group of conditions in which the muscle contraction of the heart is irregular or is faster or slower than normal. Some arrhythmias are life-threatening medical emergencies that can cause cardiac arrest and sudden death. Others cause aggravating symptoms, such as an awareness of a different heart beat, or palpitation, which can be annoying.

Why on earth are you increasing your potassium? Unless a doctor has told you to do that stop it. Potassium is one of those things that you're damned if you do and damned if you don't. Both too little and too much potassium are dangerous.
I think you're making yourself a little crazy with worry. Try to relax and recognize you are seeing specialists who will nail down anything but right now it looks more like nothing and frankly stress is a big contributor to heart disease.
And please please please don't self diagnose, you don't have malpractice insurance, so if your diagnosis and treatment is wrong you won't be able to sue yourself for malpractice.
Come on smile,