Welcome to HCM
We understand your concerns
I went through your description. You are just 16 and I suggest you not to worry too much, because anxiety
and apprehension do increase such symptoms. If you are sure that you have these symptoms (though these symptoms are not much related to heart attack
), please visit a physician and let him check you.
Once he makes a diagnosis (I am sure that he will say that you are perfectly OK) follow whatever advice he gives and stop worrying. Don't be lazy. Exercise, eat good food and enjoy the life.
Hope this clears your doubts. Available for further clarifications.