How long have you had these symptoms ?
three days thanks for asking
The description of the green vomitus sounds like bile, which is secreted by the liver, through the gall bladder, to break down fats for digestion.
Nausea, stomach pain, burping, and poor appetite might be gastritis, or inflammation of the stomach lining.
One of the causes of gastritis can be chronic bile reflux.
You may have this, as bile refluxed, or backed up, into your stomach, and then you vomited it.
Gastritis, symptoms and treatment:
http://heartburn.about.com/cs/articles/a/gastritis.htm
Gastritis, causes:
http://www.merck.com/mmhe/sec09/ch121/ch121b.html
You may need to see your doctor about this.
Regarding the possible fever, check your temperature and record it in the morning, and later in the day.
Your doctor will need this information to evaluate for infection.
You're right, this doesn't sound like influenza, which is a respiratory infection, with symptoms of high fever, severe headache, severe muscle pain and fatigue, and dry cough.
Wishing you the best,
Carol