I can relate as well. I stutter when I'm put on the spot, interview, or public speaking. Just let the interviewer know beforehand (either when you're on call with them or with an email/text) and it should take some of the pressure off. When I was a kid my speech pathologist told me to take a deep breath before speaking so that you have enough air to get the words out. If it helps you to look at your mouth then I would look at yourself during your interview if you can see your face on the screen.