Whats wrong with me ...? Help..

So... Ever since I was little iv bite my finger nails ... Then I started biteing my toe nails too. Once I badly had any nails left I started picking at the skin and eating that to. THEN I discovered finger nail clippers. Oh the finger nail clippers are bad ... I figured out if I use them I get dig at my nails and clip off more skin and nail. Sometimes I do this until I bleed .. I'm not a cuticle picker just simply nails and the skin around it. Then about a year or 2 ago I started picking at the skin on the heels of my feet. I noticed that I could use a needle or nail clipper to literally rip thick layers of skin off my heels ... And eat them. I don't know what's wrong with me and what made me start doing this. I can't stop! I have tryed for YEARS I'm now 15 years old turning 16. I can't even wear flip flops or use my fingers to point things out or anything because I'm scared someone might see them ... Is there anyone out there like me? What can I do to stop ?