how do you know when someone is trying to push you to your best, or trying to break your spiriit?

I can't understand this guy. This director I'm working with... Is he trying to push me to do my best, or break my spirit? One performance... I'm brilliant, fantastic, wonderful! The next I'm emotionally blocked, all of my character's are the same, my performances (all of them) are not good, I'm just saying the words??!!! WHAT. How can I be "brilliant" on show and a few hours later I'm wondering why the hell you hired me. If I'm that awful then why am I here? And why do you continue to direct a show that has been running for a month? He wants me to sob, not only on stage, but in front of him. If I'm sobbing, how can I perform? He says, "you should loose it" when referring to on of the characters I portray. Maybe I just don't get it. I'm really confused and really torn by all of this.