It’s almost as if I wrote this post. Im literally in the same situation as you. I’m 25F and I’ve had multiple interviews this week, both for work and grad school. When I prep for interviews, I almost have to dumb down my script because I know I won’t be able to say it smoothly. Have you tried asking for accommodations for the interview? Or just letting them know that you have a stutter and it is only apparent during interviews etc?