If you accidentally share sensitive info in a post, delete it as soon as possible.
Do NOT edit it, because editing leaves the sensitive info visible in the previous versions of the edited post. (The reason previous versions are visible on edited posts is to prevent "bait and switch" abuse tactics from editing.)
If you want to keep most of the post intact when you delete it, select the "Delete & Re-Draft" option. This deletes the post but puts a copy of it into the post creation box.