Thanks for query,
it seems that you have got Anxiety
Neurosis with Cardiac Neurosis
I assure you that go for ECG and report will be normal.
Just to rule out any cardiac problem better to go for ECG.
Develop self confidence and make your mind strong and you will be alright.
Your problem is with the brain and not with the heart !
And suppose you have got some problem in the heart then also nothing to worry as it has got remedy too.
Leave the fear and go for tests and I again rest assure you that you have got no heart ailment.
Ok and bye.