For me this song stitches tell how hard he suffer for the girl he love that he can't love him back. That the girl never love him in the fist place she just pretend that he love him, and then when the boy discover the true feeling of the girl for him he hurt so much but the girl didn't care even a little for him. Like the song says "You watch me bleed until I can't breath I'm shaking falling onto my knees."