Thanks for your thoughtful post. I have my "days", as well. I think we all do. I too try to limit my posts if I am having a rough go.
The trick is to catch oneself. If it doesn't feel good after, it probably is going against your personal grain: Perhaps stooping to a lower level, falling for the bait, whatever. When I get to a gray area, an area where I find myself doing that (lowering myself or my standards), I recognize what I am doing (it is reacting really) and I will go back and delete. Or ask for my posts to be deleted.
It isnt worth going against your true character and goodness to try to fight a point. It is futile because the other person doesn't hear you anyway.
People who don't care, don't listen or try to understand other points of view. Or the posts just don't make sense.
I have learned from my T that those are times too when someone else may be really stuck or struggling. Or having a rough go when they become fixated like that).
You are very wise. And kind. I too commend you and extend many thanks for your post