Oh my gosh ive had this problem for years and year and years. I have severe bodily acne though so that what was always the excuse i gave for doing it. I disassociate really badly when picking - i can go on for hours. My chest, back, arms, tummy and thighs are really badly scarred. I just finding it so calming though. I don't know if it can be classified as self harm but i do that also - its like theres no end to it really. I know EXACTLY how you feel though. Your not alone