this is EXACTLY what happens to me, and I don’t know what to do. Did you end up finding anything that helped? It’s the exact same for me, it’s worse in large group settings (and if i’m in the back of the class where I have to RAISE my voice, i understand completely what u mean when u say a microphone wouldn’t cause u to stutter) and then when I tried speech therapy, I never stuttered in front of them ether!😭