Since last year, I couldn't stop chewing at my fingernails, and never let them grow long enough before chewing at them again. More recently, about the beginning of this school year I've started grabbing pencils, unfolded paper clips, basically anything I can find and tearing away at the skin under and around my fingernails, digging under them and drawing blood. I don't know why I can't stop doing this, but I think it's because I think it will somehow make my fingernails shorter. I haven't done it in the past few days, but I still keep angrily chewing at my nails. Help?