I am more of a stammerer. I have starts and stops, long pauses, incomplete sentences, I'll start a sentence in one way, then finish in another. Loose my train of thought.
My mind works faster that my ability to speak, words fail me, I have a "picture" in my mind of what I want to say, but lack the ability to translate into words. I like precise, accurate speech, I aim for that when speaking, and I often get tripped up by my inability to be fluent.
It is frustrating, happens most when I'm stressed, having to talk about uncomfortable or unfamiliar things, or when being pressed on a subject, say having to talk about a problem with a work project.
It can magically disappear when talking about things I am really interested and excited about, and there are a few people with whom I seem to be able to "speak freely" with.