I'm sick and it won't go away!?

I'm sick, like everyone else in the world, typical cold/flu symptoms. Sinus infection, drainage, sore throat, runny nose. All my symptoms are related to my head/nose area. The thing is it's been going on for 2 months and I've endured two fevers and these symptoms have been on and off. I've taken 2 different antibiotics; amoxicillin and z pak. After taking them my symptoms would go away and then come back. I have this feeling like somethings wrong, I need suggestions as to how to conquer this lingering sickness.