Would like to add. Your breathing isn’t necessary to be full You could have just a tiny gasp of air , But be calm and there should be no gap between transisitioning between breathing and speaking , And the more calmer the breathing the better . What i think is happening , i think as pws stutter something along the breathing tract spasm/close Which causes a stutter using this technique you are like forcing your body to keep your tract open Which help to strengthen good speech in your brain I hope with time and implementing this technique always and in different Situations this way of speaking will grow over the old way and hopefully will become automatic I really hope this technique works for you , if it does not no worries , i hope something else will