This will sound strange but I have had similar moments. What helps is when I clear my throat. I make a sound by clearing my throat. When I hear it I realize it is me making the sound. I realize nothing bad happened. And than I say a work and I am back. I have never understood why that happens. I know at the same time it is happening I am often thinking that I must be very still and quite. But once I hear my sound and know that nothing bad happens I feel relieved and say a word. Than immediately start talking out loud amongst ourselves. I hope this might help.