I tried to read this whole thread but there is so much BAD information here!

Owlkat and Alice had some good ideas (but anchovies!). Anyone who uses any alcohol while they are singing is an idiot. Alcohol deadens the nerve endings starting with the tongue (so no enunciation) then the lips (mumbling) then the ears (can't hear how off you are).

Genie, there is a bronchitis virus going around. It is a virus and cannot be cured with antibiotics. Unfortunately, you just have to ride it out and it may take many weeks.

Anti-hystamines dry out your vocal chords. Do not use them.

You may be getting laryngitis for several reasons: Allergies, dryness, infection, or strain. Find out which one it is before you fix it.

I suggest to my voice students that they gargle with hydrogen peroxide if they are prone to infections (warm salt water is nearly as effective). Also, if you are a vocalist, you must be practicing vocal exercises AT LEAST one hour per day, just like you practice your instrument. Warm (not hot) light tea (steep not over 3 minutes) can be an excellent warm up before a gig. Of course, always tune your voice when you tune your instrument before performing.