I was in the same boat as you. Stutter/stammer/stopping since i could speak. Not terrible, but enough to eat at me at times. I joined the USAF. Had to say "airman" a lot and about 80% of my stutter goes into words that start with vowel sounds. You just have to try your hardest to speak, as idiotic as that sounds. I've found lately I've been stuttering more, and immediately I relax my core muscles(as I've found they're tensed a LOT of the time) and am able to speak clearly.