I had it. Took about 4 weeks to get completely over it. The worst was on about day 5 or 6. Fever, chills, achy. After that it was mainly chest and head congestion, coughing, and some headaches. Nasty stuff. Haven't had a bug this bad in several years. Don't know if it was flu or not, but the Dr. put me on antibiotics that did absolutely nothing.
Antibiotics won't do anything for viral (cold) infections, which is mostly what is going around now. It is a butt kicker. Not much to do except hang on tight. It will go away, it just takes some time.