vasovagal syncope

approx every 2 years i have a bout where i wake up in the middle of the night with stomach cramps/pain like i have to go to the bathroom and i also feel nauseated, as i get up i feel hot and sweaty and start to feel as though i will pass out as i let someone know in my household that im gonna pass out, there i go hitting the floor and i seem to be out for about 2 minutes when i come around i throw up and go to bathroom all over myself while i lay there weak and confused...im really scared that this will happen to me when im alone..can you give me some insight to what this might be...the same thing happened before with stomach pain. i also passed out with pain when i had a small tattoo on my hip which wasnt as severe as the other episodes but i had a hard time with the pain... i am a healthy female and eat very good i get plenty of fiber and exercise regularly...please help!