Hatred.

A girl, trapped inside depression. She has nobody, she's useless, self-centred and there's no way out. If only she could escape this hurtful world. Depression takes over her self, she has no way to show how she's feeling. She uses her fear as confidence as you say, a smile shows her weakness but, nobody can see behind the darkest lies. She finds out her mother is alive, and goes on a journey to save her before it's too late.