Honesty I think my brain just wants to play tricks on me, whatever word I NEED to say (my name, the job name I’m applying for, certain specific lingo etc) my brain won’t let me. Since I’m self conscious about my stutter I tend to think in my head that I’m not going to be able to say the word that I want to say and often enough I can’t say it, what I find helps is TRYING not to overthink shit, get out of your head and think about something unrelated to whatever you are about to do that is making you anxious. Helps me underthink shit which I need more of