Hello, Very likely you are having a viral infection. Generally, this is a self-limiting condition and should be better in a total of 7 days. Meanwhile, you will need to rest, eat and drink frequent small amounts of food and water and may use Omeprazole 40 mg 30 minutes before breakfast for the stomach pain and Paracetamol 500 mg and Ibuprofen 600 mg every 6-8 hours after food to help with the headache. If no better with the above measures in 2-3 days or if you notice any worsening please see your doctor. I hope this answers your query. I remain at your disposal in case further medical assistance is needed. Kind regards, Dr. Antoneta Zotaj, General and Family Physician