My speech therapist tries to get me to do this. It’s a lot of work. It’s not necessarily just saying to yourself “it’s okay you’re too anxious” “or calm down it’s okay”…it’s more getting yourself to FEEL those things. Thoughts and feelings are two drastically different things. I’m working on that same thing. But it’s hard, especially when you’re out in a situation on the spot…and you start stuttering, you can only feel anxious and rushed, (and for me embarrassed.