There are a couple of excerpts from the book Warm Bodies by Isaac Marion that really got to me. It's about a sentient zombie, but could apply to stammerers equally well: “In my mind I am eloquent; I can climb intricate scaffolds of words to reach the highest cathedral ceilings and paint my thoughts. But when I open my mouth, everything collapses.[....] There is a chasm between me and the world outside of me. A gap so wide my feelings can’t cross it. By the time my screams reach the other side, they have dwindled into groans.”