I have read about that as well, stuttering definitely is a vicious cycle. You don't want to stutter, so you over think when you speak which leads to more stuttering.... Its a vicious cycle. ​ I have a very serve stutter, in certain situations I basically cannot speak at all, I block on a word for over a minute . Mine is definitely heightened by anxiety, but it is always there it never really goes away completely. Breathing exercises work very well for some people, this is when you take a deep breath before speaking and speak on the top of the breath, so you essentially push the word out. This is what the Maguire/starfish program teach in the UK. I have been to both and they don't really work for me, this is why I think my stutter is neurological, but for other people on the course it completely removes their stutter. So that might be something you can look into.