Do I have the flu again or do I have a sinus infection

Patient: I was taking tamiflu75 mg twice daily for 5 days for the flu. I began feelng better while on the Tamiflu for 5 days then I started having fever, being very tired, cough and mild shortness of breath a little over a week following my last visit to the doctor. I no longer ache or have any other complaints. What do I have? the flu again or what?

Symptoms: Fever, very tired, cough and being short of breath