The one thing that helped me the most in gaining control of my stutter was to stop trying not to stutter, but to stutter easily. This took a huge change in how I think about my stutter. When I have to speak in a professional space or a presentation in front of many ppl, I stopped trying not to stutter, as that only made me stress, and stutter more. Instead, I accepted that I would stutter, and focused instead on slowing down my speech during the stutter, drawing out sounds, relaxing my jaw and focused on remaining calm and composed, and getting the sounds out in the calmest, smoothest way possible. This inevitably disarms my stutter, and gives me back control. Hope this helps.