Speech therapy helps but it’s not a cure. I tried speech therapy when I was 14. I learned the basic relaxation exercises and techniques. But as a teenager I was like, “this won’t work”! I tried for a few months and then gave up. But I noticed my stuttering would improve by a lot if I just spoke slowly. So as I grew older I decided to make some changes. So instead of blabbering everything in my head in one breath, I decided to reduce the number of words I say and then take a deep breath before the next. This has helped a lot. And I would intentionally put myself in situations where I would have to give my opinion. I’m a non native English speaker and I decided to pursue a higher degree in the US which would put me in a culture which is known for being outspoken and very direct. As you said it’s all neural conditioning. Once I was in the US I decided to speak to anyone and everyone to get over my fears. And this has helped a lot. I stutter still but it’s not something that would make me stop and think.