Look into a stuttering prosthetic such as Delayed Auditory Feedback (DAF) or the Edinburgh Masker. They are life changing devices and help most stutterers. Bad speech (stuttering) is analogous to bad vision and or bad hearing. If you have bad vision/hearing you use a prosthetic (eyeglasses/ hearing aids) and the problem is usually greatly diminished. Same for stuttering - use a prosthetic (DAF or Edinburgh Masker) and the problem is usually greatly diminished.