Been picking my arms since is was 9.

Im 16 years old and have been picking at my arms since the 4th grade. I never knew why I did it until just recently. I always thought it was some type of bad habit I acquired. My arms are covered in scars from my wrist to my shoulder and in the past 2 years I have started to pick at my chest, neck, stomach, and scalp. Im afraid to wear short sleeves and low cut shirts in case someone will see what I've done to myself but i cant stop. I'll just be sitting there and then I'll realize I'm picking my arms again. When I looked up the condition and read the description I started crying because it is EXACTLY what I do. I thought I was crazy for so long because I didnt know why I couldnt stop. This site has helped me in so many ways. Thank you!