Thanks for writing your query.
After reading your query, it seems that you might have suffered from vasovagal attack.
In this the blood pressure lowers down resulting in decrease supply of blood to brain leading to fainting
You should get following investigations done :-
1. Blood pressure and heart rate
3. Serum electrolytes.
5. CT scan
Whenever you start feel such symptoms, lie down with head end lower than the body. This will help in increasing the blood flow to the brain, resulting in quick recovery from the symptoms.
I would suggest that you should get yourself clinically examined.
I hope this is helpful to you.