As a fellow stutter, I also speak way too much... I was way too bubbly for my own good. If I was to travel back in time and was only allowed to tell my younger self one thing, it would be to shut up and bide my time. Once I was 19, I would move out, get speech therapy as a more mature adult and it would work better than it did when I was a kid. I both repeat syllables and block. I don't prolong vowels so much because I block before I can get them out.