Picking Finger

I constantly pick at the skin around my fingernails. They are so torn up that they bleed and scab over.  I tell myself that I will stop once they get to a point that I feel is worthy, but when they start to heal I just keep doing it.  I don't even realize I do it half of the time.  I am anxious a lot and if I am more stressed I pick harder and bleed more.  I am the only person I know with this habit.  I want to stop it. forever.