I have been a teacher for 15+ years. Some of my early years were hard when I taught technology. I couldn’t say the word technology and a few other important words. If I could I would substitute words but in teaching that is frequently impossible. Mostly I did and still do breathing tricks when I know a tricky word is coming up. Also quick meditation. Between classes, before school I take 60 seconds-3 min to relax, deep breath, visualise my teaching and how I will sound. Best of luck!!