not working?

The symptoms of what I thought was a cold became worse after 6 days. With a brutal cough and fever of over 100°, I saw my doctor 5 days ago. He started me on a Z-Pak, which I finished today. Cough and fever are still present and now my throat is becoming more sore. I phoned my doctor earlier today. He told me to phone back in 5 days if I am not feeling better. Other than switching doctors, I am opened to suggestions.