You reaction is so familiar to me. Please know the shame comes not from the interaction, but from years of internalizing judgment, real and imaginary. Basically you’re being triggered—it’s a form of trauma response. The good news is, you will have time to know this people and built better interactions. Then, you can take time to look at your shame and learn to understand it and be compassionate (hint: you have NOTHING to be ashamed of). Challenge yourself with low-stakes interactions where you might stutter or not, and where the result is not a big deal. Be open to accept that it was not a big deal, and build on that confidence bit by bit. Good luck!