Bloodstain noticed that any novelty in speech production alleviates stuttering. So your case is perhaps different. May I ask you a question: is there anything that makes your speech more fluent? If as you said acting doesn’t help you may be it means that you accepted yourself as a PWS person. Perhaps it is not so bad as many PWS have hard time trying to accept their personality as is and continue to live full lives. I knew such people and even envied them…