I have had a problem with lip biting since I don't know when, I've noticed I tend to do it when I'm nervous or stressed but it's not just lip biting I'll begin to take my fingers and like stretch out my lip till my lip is chapped then I would start to bite my lip, mostly the inner part of my lower lip a lot of the time till it begins to bleed, sometimes I woundnt even notice I'm doing it, afterwards once I have noticed I will have the urge to put my finger over the cut and leave it there even though it stings after a while it will begin to throb and then I stop. I don't really know what kinda of answer I am looking for other than I guess is this normal?