Fear of heart attack. Any other tests?

Hello doctors, 1.5 years before 1 experienced heart palpitations (heart beat so fast). That was the 1st incident in my life.. After that i felt 4-5 times in the span of 6 months.. only heart beat so fast no other symptoms.. Every time happened this i took ecg, echo, Tmt, chest xray, and all reports were normal.. But i could not believe the reports, the fear of heart attached occupy me. I took 4 ecg, 2 echo, 2 tmt, 2 chest xray, 1 thyroid, all report were normal. The last episode happened to me was jun 14 2022, i took ecg and it's normal.. Even repeated tests came normal, i could not overcome from the fear.. i always think something happened to me. So please advice What is the problem to me? What should i do?? Should i go for any other tests? I ccan't live happily.. please help me doctor..