((((safe hug)))) Eva, yes... it still happens to me when I allow myself to become over stressed. Of course, sometimes, like with your situation, there's no way to prevent the situation and because of our PTSD, it can be totally out of our control...
.... I still stammer when overwhelmed. I can do ok when discussing a topic in general... books, pets.. children... but during the time I'm overstressed.. not only might I stammer, speak haltingly, on those topics, but anything that includes me, my feelings, my thoughts... IT ALL STOPS... thoughts stop... the words I try to form.. just won't "get made"... and if I allow myself to become frustrated, it becomes worse! I feel like a bloomin' idiot!!!!
The best thing is to realize when you are becoming overwhelmed... and then absolutely put your foot down and stand up for yourself and the need for space and peace. (I understand where you were at on this, though. I, too, have been geared up to go into a safe place, needing it desperately, and had it pulled away. I become quite suicidal at those times..as I have no control over my thoughts and feelings then.

)
Then... if you do become overwhelmed... it helps to not beat yourself up over it... remind yourself THIS IS THE PTSD!!!! THIS IS THE NATURE OF THE BEAST!!! It's not "me" it's not the way I would do it if I could... and try to go with the flow...
the more destressed you can become, the less you will stutter.. actually, it's a great indicator for you.. when you have missed all the others that say SLOW DOWN I'M STRESSED... go to the movies, go to the library and hide... or to the beach alone...or whatever... shut off all phones, don't return calls, don't pay bills, DON'T do anything that is stress.
You've reached your max. You can't do more. Stop... and give yourself a break. IT isn't you... it's the PTSD.