I'm 30, 5'11" 165lb, don't smoke, drink or do drugs, no caffeine, only drink water, eat healthy-ish, not exercised in 5 years after palpitations started (pacs, sinus tachy, cardio says i need to but so stressed, could it help palpitations and stress?

Palpitations: I assume your thyroid is not overactive and that you have no structural heart disease by EKG and echocardiogram. I recommend a treadmill stress test to determine whether exercise worsens your atrial irritability. If not, then start an exercise program. If your Pac's are symptomatic taking a beta blocker should help the atrial irritability and,perhaps,even your stress.