Feeling weak and nauseous for 3days. Three days ago I had about 5 bananas on an empty stomach. Straight away, I started feeling nauseous and felt my stomach burning. I vomited about 3hours later. For the next 24hours, I vomited whenever I ate. It has been 3 days now, and I have been feeling weak and nauseous the whole time. My stomach also feels light and I get dizzy when I stand or sit. I went to the doctor on the first day, he said I had a chest infection and gastritis. He gave me an injection for the vomitting and he prescribed Augmentin, Neutrazole-D(omeprazole & domperidone capsule) and cold and flu day releif tablet.