Something in my chest

"And I was afraid of him... What was I afraid of? I was afraid of something in my chest, moved by his calm, deep gaze, and his narrow smile, like a glimpse of distant hope. When this thing moved, I felt a heaviness that almost held my breath. And sometimes this thing was sharp, as if it were a knife tearing my lungs apart.. I was afraid of this thing! Do you understand?! Do you understand what this thing is?!