Pretty good chance you were hacked, happens all the time with instagram.

Happened to me, they don't like it if you don't sign in regularly and so they deactivate your account whenever they please. You can contact them to get it reactivated :)

They're finally enforcing their endgame policy: post every day or get your account disabled

I got a Facebook warning and suspension for criticizing the local PD. Why? Because I felt that allocating resources used to help the homeless to the PD was an unnecessary and wasteful endeavor especially with the spike of homelessness in the city. A fact that I backed with facts and zero swear words. Apparently Facebook hates opinions, even when they aren't posted.