hi there, your symptoms are suggestive of a gastroentritis, and the yellowish green substance that you vomit out is usually bile. I would suggest that you take plenty of fluids and go easy on the food. Try taking soft boiled or non oily stuff for a day or two. You can take plenty of yogurt and some probiotic
tablets. If your condition worsens then you may need to visit a physician and get your self investigated for any bacterial infection., but otherwise usually these are self limiting condition and you should get better in a day or two. Take care not to get dehyderated by taking plenty of fluids inthe form of juices or electrolyte powder mixed in water. If you develope worsening of condition by fever
or intractable vomiting
or loose motions then go to the ER immediately. Take care.