Glossophobia, or the fear of public speaking, often comes up in lists of greatest fears. Such anxiety can often impact voice control leading to stammering or feeling like there is a "frog in your throat." A researcher from the University of Missouri has found that there is more to vocal issues than just feeling nervous and that stress-induced brain activations might be to blame.
source https://www.lifetechnology.com/blogs/life-technology-news-blog/frog-in-your-throat-stress-might-be-to-blame-for-vocal-issues