i do the exact same thing, anon. i was manipulated and gaslit for most of my life by friends and have had people spread false rumors about me, so for a while ive always been incredibly clean in my messages. i always type out things assuming 100% they'll be screencaped or read out loud to someone else. i never act mean even during arguments, i never insult anyone directly or talk shit about them with others i know, and if i do talk about them i talk about objective facts or how i personally feel regarding a situation (again, never insulting or shittalking). i word my stuff carefully so that no one can accuse me of something untrue based on the amiguity of my words, and whenever i have a fight with someone i backup as much of our chat history as possible so nothing can be taken out of context. i also consciously make the decision to be as kind and helpful as i can to as many people as possible, bc it helps me feel like if im nice to people and make the effort to listen to and understand or help others then they wont have any reason to believe any bad stuff they hear about me.
i know im a lunatic for this, or so i feel, but for so long ive been manipulated, gaslit into thinking i did or said or am things i am not or did not say/do that i just can't trust anyone anymore. the only people i trust are years-long close friends & my SO. this is my only way of protecting myself from shitty people.