It doesn’t hurt to know how to speak anatomically and scientifically speaking, practice also doesn’t hurt. What helped me, I’m still practicing, but I’ve got good results so far, is to purposely stutter. Actually Try to stutter don’t fight it at all. It’s a psychological shift that has helped me so far. Also, I’ve been in counseling and therapy which could help you personally and professionally. Maybe it’s a psychological issue they could help you with. I know I’ve benefited a good deal.