For the majority of the day, I feel totally fine. I'm not experiencing head aches or any sign of illness like a cold or fever. Then, at sudden random times of the day, I feel really sick like I'm about to physically throw up. Then, after five minutes, it's gone. I feel fine for the rest of the day. It usually happens once a day, most commonly when I've just eaten, but some times they're totally random, wether I'm getting dressed or doing a chore, etc. The sudden feeling of sickness is very worrying as there is no pattern to the random attacks and it never usually occurs more than once a day. 

Do I have some sort of flu? Why is it so random? Why do I feel fine for 99% of the day? Please help x