Based on life events.
You had locked yourself in your pitch black room, hiding under your blanket, sobbing into a pillow and biting your nails to the point they bleed. Your eyes puffy and red with tears, sad music playing to try and cheer you up and get you out of your mental state. Not feeding yourself, not communicating. Why and how would you communicate if you can't even think straight? So you have to communicate through writing, how you really feel. And that's what you've been trying to do, but words don't do anything. Drawings express more. At least that's what you thought, that's what's been keeping you occupied the past two days.
He doesn't know that you know.
And you don't plan on telling him until it's gone too far.