I can relate due being lawyer that stutters sometimes (stuttered as a kid and stutter went away, but came back when I was 18 years old), but over the time I found that mental cue of "slow your speech speed by a million times" works a lot and thought "I don't care if I stutter, they must hear me out anyway" works like a charm since my stutter is just related to my emotional state. The less anxious I am, the better I speak.