When you're in the editing room, as a director, you get the opportunity to look at your work. As a writer, you can rewrite. But as an actor, unless you're watching playback, you really rely on the director to help you.
And then the really awful thing is that at the end of the day after crying and experiencing things, then you look at what you've written and you're like, 'Hmm, there's half a page that's good here.' Then you throw out everything else.