Sinus Medication Solution

i’ve had a sinus infection for the past few days. i’m feeling better now, but breathing through my mouth all day has taken it’s toll on my singing voice and throat. my throat feels raw, and i’ve also been coughing. i have a very important audition on wednesday, and i really need it to be in perfect shape. is there any kind of quick-fix or something that could help? i appreciate any help!

Currently taking cough medicine and Biaxin to treat a sinus infection, and to give me some relief of my cough at night. I’ve seen a doctor, and everything is going okay so far.
Except for the fact that I have a hoarse voice. I am drinking Tea with Honey, sucking on throat losanges. I am getting some relief. Anything else I can do?