It's possible you suffer from trichotillomania. I had a friend in grade school who had this condition before it was understood.
From the Mayo Clinic: " Trichotillomania (trik-o-til-o-MAY-nee-uh) is a disorder that involves recurrent, irresistible urges to pull out hair from your scalp, eyebrows or other areas of your body, despite trying to stop."
