I'm sorry to tell you this, but that is at the end. Just close your eyes once the whole screen goes black. Also slender doesn't follow you around (yet). The only time that ending happens is if you stare at slender (right next to the spawn) and when you win (collect all the pages). If you don't like the staticy sound of the end, I'm about to update the game where it won't play if you click on the sound icon.