Have you tried toastmaster? and did you stop talking when you feel your words blocked? I've also tried many methods you have listed, the only method truly that works for me is to just try to talk like a normal person. What does that even mean? Well, you just talk. and stutter, and talk, and stutter. And of course, I have developed my own training and regime to prepare for getting out of the building. But the bottom line is just to talk. I don't know how many times I have embarrassed myself during a presentation. But doing it so many times, I know it's not gonna kill me. So I did it again and again and again and again. Sometimes I just randomly came to a conference, waited for the Q&A session just to give myself an opportunity to raise my hand and speak up lol. At first, I was f\*cking nervous and stuttered, but at my next attempts, I was so looking forward to it. I almost feel like I'm numb and feelingless to fear of getting embarrassed. People sometimes would remember me like "oh that guy who stuttered at the last conference" But man who cares. I have been doing this for 10 years. 10 years full of embarrassment and humiliation. But my stuttering has never been better. My only advice to you please not accept your stutter as you will get even drown in an even deeper part of the ocean. Just keep on talking buddy. Goodluck!