Colloidal silver.
Someone told me to also get some Oil of Oregano. Do you agree?
Yes. Oil of Oregano is a powerful antibiotic and anti viral. We take it all the time at the first sign of a cold or upper respiratory infection. Usually it knocks it right out or shortens the duration and intensity. Make sure you get the 70% strength.
Essential oil of oregano is some pretty powerful stuff. There are a lot of natural antimicrobials around, tea tree oil is another, do some research. Most are topical, meaning meant to be used externally, not internally. You may be sensitive to one or the other, so discontinue use if you get skin irritation, redness, rash from them.