does any sound come out when you try to speak? Raspy or squeeky? If so, Clarity's suggestion sounds really helpful (i will have to try that for when that happens to me in that way - like now).
Or is it like you've gone mute?
I have a selectively mute alter. It happens in therapy or in public - the words are there, but the throat won't work, the mouth won't speak. But I've not had it continue longer than the trigger.
sending hugs!