i have this problem or at least something similar. it’s called cluttering. my brain works way too fast for my mouth. sometimes i’ll say a word and i completely will leave out the beginning sound and end sound and it can be hard for ppl to understand me. i have really bad social anxiety bcs of it. ive trained myself over the years to talk slower which was kind of hard. but it helped me to form my words correctly. you might have been told already to speak slower maybe during speech therapy or something but idk this is what helped me :)