I'm now on day 10 of feeling shit. The first 4 days I was mostly in bed, then felt a bit better for a day, then relapsed. In bed again for a day then thought I was on the mend. But all the symptoms came back the next day!
It's not flu because I haven't got a temperature and the sneezing has been off the scale. I've got a terrible cough. It started with a constant headache but that's gone now.
If you have got it I recommend Night Nurse.