I Have Been Sick With A Cold, Coughing A Lot,

I have been sick with a cold, coughing a lot, wet cough(green) fever only one night. Dr. gave me nothing said it was viral. Now I have a fever blister, had them in the past and then they go dormant. Call Dr., gave me in kenolog cream, I told the nurse I had Denavir in the past but NO. Which is the best ?