How do I tell my parents and get help?

I am 16 and have been picking at my face, shoulders, back, lips, legs, and the sides of my fingernails few years now. I was not aware I had an actual problem and that other people did it too until a few months ago. I am embarassed about my condition and have only been able to tell 3 of my closest friends. However, only one of them has shown any real concern but there isn't much he can do to help me. Neither of my parents know. My mom has noticed a few of the scars on my face but she is completely unaware of the extent of my picking. I am tired of always having to wear long sleeves and long pants to hide my scars. It's gotten to the point where I will avoid doing anything that would require me to show any skin besides my hands and face (If I could cover up my face, believe me I would.) I feel like I am unable to live a normal teenage life because of my dermatillomania. So my question is, what is the first step to take for treatment? Can I get help without my parents having to know? If not, what would be a good way to tell them? Thank you.