Acting is the ability to live truthfully under the given imaginary circumstances
Don't be an actor. Be a human being who works off what exists under imaginary circumstances.
There's no such thing as nothing.
The greatest piece of acting or music or sculpture or what-have-you always has its roots in the truth of human emotion.
WHY is the most important word in an actor's vocabulary.
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.