Dermatophagia - Skin biter. I need help.

I can't remember why I started biting the skin around my fingernails and the insides of my lips and cheeks but I remember I was about 8 or 9. Im 22 now. For pretty much as long as I can remember remember I've been tearing skin off of my fingers and from the inside of my mouth. Currently all but 3 fingers are bleeding a sore. I didn't have the best life growing up, my family had a lot of issues. Also, I work on commission so I know the stress of my job plays a part but I'm not usually worried about anything when I do it. I just don't realize I'm doing it or I see a piece of skin sticking up and I get the strongest urge to bite it off and I can't control it. I have no idea how to stop this. Until yesterday I thought me and my sister were the only ones who did it. I did some research and it led me to here, where I see other people have problems similar to mine. I've always had to get every piece of skin left around my fingernail and my intention is never to make myself bleed or actually swallow any part of it but I can't stop myself. I get crazy looks all the time and people ask what happened to me when I'm wearing 4 band aids on the tips of my fingers (because at this point, once my fingers start bleeding, it takes a long time for them to stop) but I've tried to stop but have had no success. My coworkers all just say "just don't do it, it's that simple" and every time they see me starting to chew they say something but it got to the point where we all just gave up. I also pick my skin. If I have a bump or scab you can guarantee that it will be a bleeding hole in my body within 5 minutes of me finding it. Does anyone else have any suggestions for me? Can anyone help?