The literature for metoprolol says to not stop taking it on your own accord and not suddenly. I did, but on doctor's instructions. Like you, I had a low HR that made the back of my scalp and neck tingle. Not only that, a nurse came running into the ICU cubicle my wife and I were in only to find me chatting amicably with her. Her eyes were wide, and she held out her two forefingers about eight inches apart and said they'd all watched my heart pause 'that long' on their monitor. The attending consulted with the gentleman electrophysiologist who had performed an ablation of my pulmonary vein mouths to rid me of near-persistent atrial fibrillation. Between them, they agreed to start me on the huge hammer called amiodarone...literally the drug of last resort for people with heart arrhythmias that don't respond to more commonly prescribed AAs....anti-arrhythmic drugs. I had had my last dose of metoprolol, but the substitute, a most powerful one, was to be the dreaded amiodarone.

I do think that you might have been further ahead to have taken three or five days to get off metoprolol, but I'm not qualified to say one way or another (not medically trained and I know nothing else about your medical circumstances and history). Clearly you're in a bad way for some reason. Your heart is acting up, probably (a guess) SVT, or 'supra-ventricular tachycardia', an unfortunately very common arrhythmia. Metoprolol, as a beta-blocker, reduces the strength of each contraction and also slows those contractions. It works very well for many patients with tachy-arrhythmias. Some do very poorly on it, just as some do for the various oral anti-coagulants prescribed commonly for heart patients with arrhythmia, or with the more common anti-arrhythmic drugs like flecainide, Sotalol, and Tikosyn.

I wouldn't normally make light of your situation, especially with my own history of highly symptomatic atrial fibrillation, but you find yourself in good company twice over. You've joined the crowd with a wonky heart and the crowd that can't do well without, or with, metoprolol. 😀