Thanks for your question on Healthcare Magic.
I can understand your concern.
Honestly speaking,
heart attack is uncommon in your age of 21 years.
But you symptoms like chest pain, breathlessness etc are commonly seen with heart diseases.
So better to first rule out heart diseases.
So
consult doctor and get done ecg and 2d echo.
If both these are normal then no need to worry for heart diseases.
Sometimes asthma can also cause chest pain and breathlessness.
So
consult pulmonologist and get done clinical examination of respiratory system and PFT (pulmonary function test).
PFT will not only diagnose asthma but it will also tell you about severity of the disease.
And treatment is based on severity only.
You may need inhaled
bronchodilator and inhaled
corticosteroids (ICS).
Don't worry, you will be alright.
Hope I have solved your query. I will be happy to help you further. Wish you good health. Thanks.