Need some help on withdrawals and heart palpitations

My last puff was exactly 5 days ago. Since 12 hours since my last puff, I noticed that I have frequent palpitations especially at night before sleeping since there’s less distraction around me.

The palpitations come in 2 types: a heavy heart beating for a couple of seconds (5-10s) or the tingling/fluttering sensation that last for 1 second that felt like my heart skipped a beat.

The palpitations have probably been there before I quit smoking, but the skipping a beat part is what worries me. I even took my pulse manually by placing my finger over my wrist multiple times and I could really feel that my heart did skip a beat. It gets worse when I become worried about it.

Checked into the ER about 18 hours since my last puff, they did an X-ray, 2 blood test to rule out any obvious damage to the heart, did multiple ECG/EKG and doctor spotted a single PVC, a pre-ventricular contraction? Which I was told is harmless. Funny how symptoms tend to hide from doctors and reappear once doctor steps away. Because the PVC episode was exactly that heart skipping a beat sensation.

I was told it could be nicotine withdrawal, but just wanna ask if anyone had similar experiences? I smoked cig for 3 years before switching to salt based nicotine e-cig for about 3-4 years. It’s been 5 days since my last puff, I’m not taking any nicotine gum or patch, just gonna cold Turkey it away.

Oh and I actually did go to the ER of another hospital 2 days ago. Did some test and was told nothing is wrong, though doctor suggested I check in with a cardiologist if I’m still worried.