Making A Huge Scene

Yesterday I went in to the theatre, but couldn't work since other work was being done.  Today, was able to work on the scene.  I just pooped out about 4 hours into it.  It takes complete concentration for me.  A lot of the time, I'll drop back, look at it and semi-daydream until something strikes.  From there, I may do some broad strokes or some little detail.  In the middle of those bursts of insight, I have to keep an overall structure and balance - allowing some give and take with an urge that may be a red-herring wild hair.  At the same time living with my own inadequate experience (especially painting on this scale!), but nevertheless doing something.