if you have flu, it's well worth taking tamiflu, (if it's in the first 48 hours).
otherwise you just have to ride it out. delsym is one of the few things that works for me for a cough. i like dayquil as well, but it all just masks the symptoms until it's gone.
last year i had the flu for a week, then it turned into pneumonia. compared to the flu, i felt great with pneumonia. the only problem was i was short of breath, and exhausted super easily. i had to take antibiotic and an inhaler at that point. sometimes an hour visit to an urgent care will save you days of misery.