Until vomiting stops try any of those:

• Rest as much as  you can
• Homeopathic Nux Vomica 10 pallets melting in the mouth every 15 minutes
• Cell salts
• Sip Activated Charcoal
• If cannot drink, put some Celtic Sea Salt under your tongue and then suck on ice 
• Natural electrolytes: Celtic Sea Salt and key limes in spring water; coconut water – small sips
• Electrolytes powder such as Liquid IV  – a tablespoon every 15 minutes to slowly rehydrate
• Small sips of strong potato broth made with organic potatoes (reach in potassium)
  • cut up 3 potatoes and 4 cups of filtered water; when boiling reduce to simmer for 20 minutes
• Suck on candied ginger

Hold off on any solids until the vomiting stops

To fight the infection:

• Herbal Anti viral formula
• Activated Charcoal 

When vomiting stops:

• Introduce food slowly by starting with rice, applesauce, bananas, gluten free crackers, homemade chicken broth