Over-explaining is often fear wearing a long coat.

Long explanations usually come from a fear that the plain version will not be accepted. So you add reasons, context, a defense against objections nobody has raised, and the pile makes you sound less certain rather than more. People read the length as the size of your doubt.

Say the short version and then stop, even though the silence feels dangerous. If they want more they will ask, and you can answer the real question instead of twelve imagined ones. Notice which subjects make you add the most words, because that tells you something.