I had a pretty severe stutter when I was younger. I was effectively mute through most of high school. I'd gone to speech therapy from 3rd grade onward,but none of it helped. Some actually made it worse. Then in my 20s I had a lovely girlfriend that did a bunch of research and motivated me to go to Virginia to do the PFSP program. It's an intensive program but I shit you not, I left there almost completely without a stutter. It's a lot of work, you're having to entirely retool your speech pattern. My stutter did creep back in over time, but I blame myself for that for the most part as I didn't maintain the program. Like I said it's hard work. Regardless, my stutter never returned anywhere near the level it was before. I'm now a pretty mild stutterer that has an occasional hard block. Good luck!