does anyone pick their thumb joints?

I pick at my thumb joints and the sides of my fingers constantly. They aren't scabs or anything, but now they have become really rough skin. I use a mechanical pencil, my nails, or my teeth. It looks horrible, to the extent where people ask me if I burned myself extremely bad. I can't hold hands with anyone or give people highfives. I feel so embarrassed, and I want to stop. Most of the time I don't realize I'm doing it, and I wake up every morning thinking this will be the day I stop, but it's uncontrolable. I was wondering if anyone has actually overcome this disorder, and if the scars will ever go away?