Checking blood sodium and potassium levels

Dr. I got a good one. Quick History.. I was a normal 30 Year old Smoker, social Drink, Body Builder (no supplements).. I began having problems at the Gym.. I had shortness of breath skipped heartbeats and Palpitations. (2 ER visits Nothing Wrong) So I Discontinued LIfting. Months later I woke up to a Palpitation after a night of Drinking ER visit (nothing Wrong) I quit Drinking. Months later I was smoking a cigarette like I always do and My Legs and body got extremely heavy and my heart Beat slow and hard etc. (No ER) I quit smoking. This was 3 years ago now. I have quit it all Yet I suffer daily from Weakness,Dizzy, Fatigue. Shortness of breath During Sex, Work, any exertion. at rest usually feel ok. I have had stress test, echo, ekgs, halter monitor(SVTs found), thyroid, blood work. You name it. I check blood pressure during symptoms and its perfect. any ideas. further tests you suggest.

PS no history of drug use, also if I drink even one beer, i get cold sweat,heart skips, nau