I Have A Serious Problem Of Habit Of Moving My

I have a serious problem of habit of moving my lower lip inwards again n again .. It happens itself.. I m helpless .. I tried hard to get rid but I m not able to. . I get tired and so much headache starts because of this habit.. Many times situation gets worst.. Pls for god sake help if u can.. I m suffering from 5 years.. I hv gone very weak bcoz of this...