From my previous question i'm feeling yuck in the stomach now.also feeling very tired.is it a virus?

Could be,,,: It could be a virus as this is how stomach virus/intestinal flu presents. If it doesn't go away in a week-week and a half you might see your doctor to rule out a bacterial cause.

Difficult to know: Your condition is very difficult to determine on this forum. If you are otherwise healthy, and are feeling this way you probably have some kind of viral infection. These usually resolve in several days. If this is not the case you need to seek medical help asap.

Probiotic /prebiotic: Processed foods have many added chemicals that can kill off the healthy bacteria in our digestive system. Consider starting a pharmaceutical grade probiotic daily and some organic soy sugar which has some antiviral properties. Try to avoid high fructose corn syrup.