I pick my skin and eat it?

OK, I find this totally embarrassing, but I think this might be a good way to release it. Here it goes... I am a 16 year old girl from the UK. I have always bitten my nails, even as a child. However as I have grown older, this has grown more and more. I don't bite my nails as much anymore, but I chew the skin around them until it looks like I've sliced at the with a knife. Then I peel off the skin, all the way up my finger, and eat it. It gets very sore to write with, sometimes. But the main problem I have is my left foot. It looks honestly like I've put it in a blender. I want to say I hate ripping (it is ripping, I attempt to get the biggest chunk of skin possible to come off) but I don't- I really love it. I love the feeling of it coming off (if it's painless) and eating it. But I hate the aftermath, with the bleeding and limping and how it stings. I'm also worried about infections- and also my mother always yells at me whenever she sees how I've picked at it, and whenever I'm doing it she screams too. Initially I thought it was her making me stressed that made me do it, but I've gone to boarding school- yet I still do it. Then I thought it may be low self esteem- but I think I'm quite pretty, so I didn't think it was it. My counsellor (I'm a recovering anorexic) said it may be anxiety and I should exercise to relieve stress, but that didn't work. It tends to happen after a shower where dead skin comes up. I also scratch my torso, particularly my breasts in the shower until they're red raw to get rid of dead skin. The reason I've come on this forum is because my girlfriend saw the damage and she wants me to get help. I've tried taking care of my feet by filing them, but then I just pick at tender skin and it's more painful. I try to avoid the time after a shower where I most often pick, but I just pick anyway, it's just less pleasurable. I don't know what to do...