Why I stutter? (read description)

Why I stutter? (read description) Okay, so whenever I stutter, I feel the lack of breath. Not only that, I kind of lack confidence in what I speak. Whenever I'm angry I don't stutter at all, or very less. I guess when I'm flowing with emotions, there isn't a question of self-esteem/ confidence. I'm pretty high on that, maybe I don't stutter those times. Another point, I have frequent nose-blocks and my nostrils are partially open, so I'm probably not getting as much air. So, what do you guys observe when you stutter?