New Member- Needing Advice

Hello everyone- I just found this website and it is already giving me hope. I am needing advice on how to cure this. I am 15 years old, and it's summer time. Unlike most teenage girls, I hate wearing shorts. This is because ever since I could remember I had been picking at my legs. All of my calves are covered in scars. When I was little all I would do was pick at my scabs. I have a memory from when I was 6 or 7 I believe, I was trying to get to sleep without picking this one (perfect in my mind) scab because my mom told me it would scar like my other ones. I went the whole day without doing it but when I was all alone in my room, trying to get to sleep, I couldn't resist the urge. I woke up and I picked it right off. I was so happy but mad at myself at the same time. Looking back, I'm remembering that my old sheets were covered in blood spots because of my picking. I didn't want to wake up my family by getting a band-aid and I would let the blood stay there and never tell anyone. I rarely pick at my legs anymore because they are already so destroyed. Now that I'm older, my fingers, face, feet, and lips have all been hurt by my terrible fingers. My forehead has permanent scars from all of the popped zits then turned into scabs, I have picked off. I am a dancer so I have a lot of calluses, in 7th grade I started picking off the skin and calluses from them. I have taken off skin so deep that it makes me limp sometimes. My lips are gross. I'm always biting on them and I always have scabs. My fingers are the worst. I don't bite my nails (anymore) but its the skin. I will bite my fingers and pick at them until each side of the nail has red flesh popping out from the skin. This part makes me feel the grossest, I eat the skin afterward. I do it in class a lot and people just stare at me. I want to stop so bad. My record is a week, I think. I don't know what to do. I'm so embarrassed of myself. I believe that I have a problem but when I talk to my mom she says that its just a silly habit that I can break in no time. I really think I have a problem and I am just needing advice on what works for you guys and what doesn't. Thank you all so much for reading. It means a lot to me.