For reasons I already pointed out several times (and which I don't mind pointing out again), I had severe anxiety and rejection sensitiveness when I wrote comments on Reddit, fearing their responses. Sometimes those fears were correct, and sometimes don't, but the fact that I suffered those things was enough to feel myself in danger. Twitter, Reddit, all was the same shit regarding interaction with other people.
Since I joined the fediverse and became more active, those fears were lowering. That, and the fact that I'm taking medication for my ADHD. But a good environment and friendly human interaction help too.