Nathan is describing the production of Summer Soldiers and the deterioration of his relationship with director Hiroshi Teshigahara, in which they had conflicting visions for the film.  Going through his journal entries from the production period, he notes:

"If there is arrogance in my observations and complaints [about Teshigahara] there is also an abjectness that troubles me.  Striving, and failing, to feel superior, I tumble into despair about myself, which blinds me to what I have achieved and prevents me from finding any pleasure in it."  (p 147)

This is a perfect example of the perfectionism and "all or nothing" phenomenon described by Burka, Yuen, and Ben-Shahar.