i have a similar thing when im trying to express myself ill start a sentence then its like my mind gets stuck in a feedback loop where im thinking about the words i want to use have already used and how theyll sound together then i start stuttering over a word and have to focus on getting that word out which makes me forget what i was talking about  unfortunately the same thing applies to my writing making it a rambling word smash of various half ideas makes for good creative writing ideas but terrible factual or informative writing  tldr mind too fast - words dont work