I am sorry to say this, but as a stutterer, I feel like you are at least partially responsible for your son’s stutter. Rushing a 3-year-old toddler to therapy because of stuttering, and making him do it for 7 years, honestly sounds crazy to me. A three-year-old is just learning to talk and you already instill in him the idea that there is a problem in him, that he is somehow defective. There is no way this does not make him self-conscious about his speech which is bound to only exacerbate the problem. Like an ugly person becoming aware that they are ugly. Some problems only become problems when one becomes aware of them. I too have been stuttering from a very young age, but I was not even aware of my stuttering before my mother told me about it and said that it is an issue. And yes, I was also made to do speech therapy, albeit not nearly as long as your son, but with the same lack of results. Sometimes I can’t help wondering whether my stuttering would have gone away by itself if I had not been told that there was an issue with how I talk.