I hate when this happens. Now at 33, im aware of the days when moments like this will come on. My stutter gets worse when my anxiety is high. I try to avoid being out when it gets this bad. I’m sorry you went through one of these “blocks” again. (Which by the way that’s exactly what it feels like) it’s like from my brain to my vocal cords everything I wanted to say disappears and I can’t translate anything besides “um huh..” so yes you’re not the only one my dear.