Then, you know about warming up—but what about cooling down? In general you should always warm up really well and cool down properly before rehearsals and performances, just like any other athletes would warm up and stretch prior to a race or game.
You think whispering is your life-saver, but actually… Whispering does not conserve your voice. In fact, whispering is one of the worst things you can do if you want to maintain a healthy voice. It is incredibly taxing on the vocal cords because it is produced by placing the vocal folds close together and then keeping them there. This irritated and swollen tissue keeps touching and vibrating, which further damages the vocal mechanism.
Finally, don’t sacrifice safety to please others. The director wants you to scream, growl, or make some other sound and when you try it, you can tell it doesn’t feel right. This would be a good time to say, ‘Can we bring in a voice coach to help me with this?’ If they’re not willing to bring in a voice coach, try saying, ‘Would it be OK if we mark this for today? If you give me some time to work it out on my own I can bring it back to you.’ Use the comparison that aggressive vocalization is like a stage fight and needs time to prepare and practice.