Righthand column in ‘add post’ page missing

There’s more. Basically, everything I need to do the simplest of posts is just gone — the right hand column with my categories, tags, and PUBLISH BUTTON, and all the buttons which should be at the top of the post (bold, italicize, underline, link, etc.). I’ve tried it in 3 different browsers, I’ve disabled every plugin, and nothing. I can never post again unless this gets resolved. Truly, truly horrifying.