Heart Palpitations While Smoking. Out!

Hello There, I was on a medication course of Cervical Spondylosis, and when I completed the course, I've started having symptoms like Acid Reflux, everytime i eat something or drink, I'm having immediate burps. I used to be a smoker (5-7 Cigarettes a day) for almost 3 whole years, and, it's been almost 2 months and I'm on my smoking cessation. These days even when i try to smoke and intake some drags, I'm starting to have heart palpitations. My heart races like around (150-160BPM) for atleast an hour, substances like THC also effects on my heart the same (Dizziness, Rapid Heart Rate, Burning like sensation in chest) my X- Ray and ECG report seemed normal to doctors, but, still I'm having palpitations when i smoke/drink! Please help me out when is this gonna end, Is it because of the medications i took or is it something else, please help me out!!