I know what you mean - it's no joke when you are losing income from illness. It's so frustrating. With something that sounds so serious though, I'd stick with the advice of trained doctors. Using a spray to ease a dry throat is one thing...

Generally, I also avoid dairy when I'm singing, and that includes chocolate. It clags up your entire throat! I don't usually drink much alcohol either - it doesn't take many for me to start singing off key ;-)

Liath