Hi, 
Thanks for your question. 
After going through your question, I can understand your concern. 
There is most likely possibility of anxiety attack or panic disorder in your case. 
But other possibilities related to heart and 
hormonal imbalance should be considered. 
I want to know - 
- Your age and gender.
- Height, weight, BMI. 
- Any associated conditions like 
diabetes, 
heart disease, Blood pressure or 
cholesterol problem. 
- Any medicines are you taking. 
- Any addiction or addictive substance use. 
You should consult your doctor for detailed clinical examination depending upon it there may be need for following investigations - 
- ECG, 2DEcho. 
- T3,T4, TSH. 
- 
Complete Blood Count. 
- Liver & Renal function test. 
If all these investigations normal then there is a need for psychiatric consultation & counseling and if required further evaluation. 
Hope this helps you, if so do vote as helpful.