Right, you're referring to "psychogenic" stuttering. To be honest, I haven't much about psychogenic stuttering; I've primarily read about developmental stuttering (genetic causes) and a little about "neurogenic" stuttering, which is stuttering caused by brain injuries (usually later in life). So unfortunately, I don't have much advice for people with a psychogenic stutter. If your stutter is psychogenic, I think the best route is going to a therapist. (But again, I'm not an expert on that.) However, we don't know for sure that your stutter is pscyhogenic and not developmental. If it hasn't completely gone away, then it's more likely to be developmental. And yes, 12 is a late age for developmental stuttering to appear - the research I've read says most cases start at 2-4 years old. There is another redditor (I can DM you his username) who told me his stutter also started around 12 and has been pretty obstinate, even though he's addressed what he sees as the behavior that caused it. We can't really know for certain whether your stutter is psychogenic or developmental/neurogenic unless you went through the same brain scans that were used in these studies. I think people tend to over-estimate the psychological cause of stuttering because the neuroscience underlying the causes of stuttering isn't well known. So I don't have "the answer" for you, but I would recommend trying one of the speech interventions above first, and if that doesn't work going to a therapist second; simply because the average therapist probably knows little to nothing about stuttering, and may agree with you that it's psychogenic when it may in fact be neurological. The good news is that your fluency can be improved whether your stutter is neurological and psychogenic, and that can improve your quality of life. :)