Acting is behaving truthfully under imaginary circumstances.
The only way to deal with yourself as an actor is to follow the emotional truth of what you have to do under the imaginary circumstances. And as you develop you become confident. You come to believe in what you're doing and trust it because it's out of you.
Find in yourself those human things which are universal.
The text is your greatest enemy.
There's no such thing as nothing.
The truth of your instincts is the root of your foundation.