How to keep from losing my voice, or ways to soothe it.?

The best way to save your voice would be to not wear it out. I know you'll want to practice and warm up a lot for your auditions, but don't overdo it. A common factor in wearing out your voice easily is if you strain it while singing. Your throat should be relaxed when singing, not tight. You shouldn't need to push your vocal chords in order to sound nice or to project. If you support with your diaphragm, use enough air and just let your flow, singing ought to be more comfortable. I have had this problem often, trying too hard to force the notes. It helps if you relax or massage your throat gently while you sing.

On the more practical side, hot tea or water with lemon and honey is very soothing to a strained throat. Avoid milk products, and there are even some herbal teas at stores like Safeway that are pretty useful. I've used "Breathe Deep" Yogi Tea, and it's pretty good and cheap.

So I'd just drink a cup or two of tea in the next few days, stay hydrated with water, avoid over-using your voice, avoid dairy products, and focus on being able to sing without straining for the notes.

Hope this helps!

I was in a show where I had to scream a lot... basically when you think of a "safe" scream, if means to scream from your nose so that it doesn't hurt your throat. Singing through your nose gives a bad sound, but if you scream and focus the sound there, if will hurt your throat less. Also, when you sing the high notes make sure you get a LOT of air. And drink tea! Lots and lots of tea!