hi i know how that is i to had thaat happen and i have a anxiety disorder you are so young and it probably is anxiety there are so many people who misstakes anxiety attacks for heart attacks because some anxiety attacks have the same symptoms as heart attacks
Since you have seen your doctor and have been hospitalized numerous times only to be told there is nothing wrong, then it's time to try another route. I would suggest you ask your doctor for a referral to a good therapist to find the root cause of what I believe is health anxiety.
You do NOT have to live this way! Imagine a life free of this fear.........
RubyWitch