Thanks for your question on Health Care Magic.
I can understand your concern.
In my opinion, your palpitations are mostly due to high
stress level in you.
But at your age of 15 years, we should first rule out
arrhythmia (rhythm disturbances in heart) as a cause for your palpitations.
So get done ecg, 2d echo and Holter monitoring (24 hour continuous monitoring of ecg).
If all these are normal then no need to worry for major heart diseases.
Control of stress and
anxiety are needed in your case. For this better to
consult psychiatrist and get done
counselling sessions.
You may need anxiolytic drugs too.
Don't worry, you will be alright. But first rule out arrhythmia.
Hope I have solved your query. I will be happy to help you further. Wish you good health. Thanks.