According to websites about stuttering, if your late onset started as an adult, then it's called: psychogentic stuttering. I suggest that you google this. Those websites state that psychogentic stuttering will usually go away within a couple of months (or years). Instead of a speech therapy (that focuses on developmental chronic stuttering), those websites I mentioned, will refer you to a 'psychologist' treatment. So google for: ​ What is psychogenic stuttering treatment for psychogenic stutterers