Hi! I am having exactly the same problem in college. Our exercises in college would include so much of number 8, which starts on the vowel "o" in my language. To break stuttering on those numbers, I often times start to just tap my foot like a metronome to calm myself down and to say the number on whatever beat comes. But I guess most important is to relieve your muscles :D, that tense feeling supported with stress just does not work together well.Hope this helps and stay safe!