finger and cuticle picking

I have been biting the skin from my fingers and cuticles since I was 7. I remember being told to stop biting my nails and I would be rewarded. I just changed to biting the skin. I am now nearly 60 and still doing it. I stop when I am ill in bed or on holiday so I think that is when I am totally relaxed. I also stopped once when someone said they didnt expect me to have hands like that. Also I stopped when I was going to get married and a new ring as I knew they would be inspected. Otherwise main times for picking is when concentrating on TV or a passenger in a car . So it must be when I can't do anything physically my energy goes to picking. I have achieved stopping occasionally when wearing loads of handcream but always go back to it. If you know how to stop let me know. I also know that my brother does it but non of my parents or grandparents.