@kayleighroth,
We are not medical doctors and cannot give medical advice. My question is -
What are your parents doing about this? This seems extreme with anxiety, but again I am not a doctor or a therapist - I do have a daughter diagnosed with anxiety and do know that panic attacks can impact you physically.
If you have anxiety it is a medical condition - mental healthwise and you can help with this. Have you seen any specialists that deal with anxiety? If a good doctor feels this is anxiety then you should see a specialist dealing with that issue.
As a parent - I would go that route - find a highly recommended therapist that specializes in adolescent anxiety. Get a diagnosis from them. And then get the help you can.
Just guessing you have only been seeing medical doctors dealing with the symptoms of anxiety and that is why you are getting the results you are - you are not dealing with the root of the problem. Did any of these doctors suggest on who or which sort of professional you should see to deal with anxiety if this is what they say you have? It would be completely irresponsible for the doctors not to give you a recommendation on who to see as anxiety is a real issue and you need to learn to deal with it or else you will keep having these episodes.
Again - I am not a medical doctor but just giving you suggestions on who else you can see to help you deal with this issue.
One other thought - you said initially you were dealing with heart related issues - what are those? Are you being seen for these with a medical doctor?