You aren't alone at all. We all have diverse modes and pacing of expression.

Some folks when they aren't doing well tend to be very extroverted, active on forums, talkative, busy.

Some folks when they aren't doing well tend to withdraw, get quiet and more introverted, hide.

And there are all sorts of variations on these themes.

Being able to post on forums isn't a requirement for health. It's okay if sometimes we just don't wanna for whatever reason.

If writing things down helps me, but posting on forums right then isn't working for me, I turn to my journal, to keeping a blog, things along those lines.

If I want to practice being more social and even sorta extroverted, works ultimately best for me to go be around people.

Your mileage may vary. I agree, it is intriguing how perspectives can differ so much. I suppose it is part of the beauty of humanity, our diversity.