My stutter is the same, comes in waves that last anything from a few weeks a year (seriously) to a few months. Nothing changes in the universe but it just starts again and can get really out of hand, I can never build up the tools to overcome it or even manage it because by the time I start doing something about it, it starts to magically dissipate again, then I'll be virtually fluent for another few months or so and I think I have it beat... but oh no... just when I get comfortable it starts up again. What gives?