Positive Anger...?

I suppose I have never really thought of anger as a positive emotion.  Until now.  It is driving me to keep going in my search for promotion; it's a sense of "I know damn well I can do the job - what am I not saying?"  And that's the frustrating thing.  Out of the three interviews I had, I am still waiting for feedback.  I might as well have spoken Swahili for all the good that came of the interviews.  So, until the anger runs out, I'm making the most of it.