As as over-thinker myself something I didn't appreciate until too late in life is the necessity of practice.

If you want to be able to hit a ball it doesn't matter how much thought you put into it - the learning is all about programming your lower instinctive brain and it only has the input device of repetition. This brain level has the ability to work at much lower latency - which is critical for reactive physical tasks.

I suspect it is the same here. You can certainly learn to speak using different levels of your brain as well. Case in point public speaking - the reason this is hard is generally you have to trust your mouth on automatic mode to follow behind and using the thinking part of your brain to better plan (or remember) ahead to build a narrative path.