Yeah, it's all in your head. I believe that with confidence we can overcome stuttering. Not completely but confidence has a lot to say. For the past 5 years my stutter has been bad, but i have also had an porn and masturbation addiction. If you know about the subreddit "nofap" i will defiently check it out. I have not ejaculated for 1 month and my mind feels SO clear and my confidence has gone up so much, that i don't even think that much about stuttering anymore, it has gotten a lot better :)