Increased heart palpitations. Reason?

Since more than a week I was having this weird feeling in my chest or a small dull pain in between. Friday when I was coming back home I went to the ER because my heart rate increased, I was scared and my chest pain increased (left side of the chest). The doctors said the ecg does have a few changes but could be old or psychological too. Trop I test was 0.90 so they mentioned this could most probably be an anxiety attack so I was suggested to visit a cardio to get a review. I was suggested Pan 40 twice a day before food and Concor 2.5 after food twice a day. I stopped as per the 3 day course however I couldn't get the appointment for my cardiologist so I haven't been to the cardiologist yet. Today i smoked but when I was smoking while leaving I was told that smoking leads to increased palpitations and I guess my body panicked but my palpitations increased. I came home and had concor 2.5, my bp was 143/93 with heart rate of 102. Now my bp is 117/84 with 82 heart rate. Possible reason?