Quary regarding thoughts. Panic atteck?

3 month ago i suffered from gas and hyper acidity at that time i feel little pain in chest i done ecg and 2d eco report its all normal . At that time my pulse little bit hugh arround 100 the. Then regular check up my pulse that is always 80-90 and bp always 120/80 and after that i visted a famouse one doc he told me its amlapitta and give me a medicine that dompan and clonzapam due to clonazapam i feel very well but he told me nw its not required then after one day i waken in earlier morning then negetives thoughts comes in mind sudeenly my whole body and legs vinrated and my heart racing too fast and pounding after 10 min all becomes normal i also visted md physician he called me your ecg normal its die to anxity .after that my thought are too much changed lyk i will be death due to heart atteck lyk thoughts .i ecperinced sudeenly heart beat increased and legs vibrated types symtomes 2 times in 3 months . Is it due to anxity or panic atteck?