The cold heart truth is that stuttering is an anxiety disorder and that all the neurological pathways are the consequence of stuttering. People might have a predisposition to anxiety and to more specifically to that anxiety manifesting in stuttering, but as long as you are trying to find a way to fix stuttering itself instead of the anxiety behind it, you will keep on going in circles forever. It's like having a panic attack and then being afraid of having the symptoms of a new panic attack again, continuing the cycle, instead of working through the memory that caused the anxiety in the first place. This is how it works with every anxiety disorder. The problem with stuttering is that since speech is such a deep mechanism in the brain, it also takes very very deep memories to work with. Good luck, you'll get over it but you will have to face painful moments. (I got over 17 years of stuttering BTW)