This is why self diagnosis is self destructive.
i've been biting my inner cheek and lips for most of my life. it's done some damage. i also pick at my nails and bite around them relentlessly. and i'm no stranger to pulling hair out, especially inner eyebrow hairs and chin hairs, but sometimes head hair.
self diagnosis in this sense is self destructive only in that it validates the behavior, in a "oh, other people do this too" sort of way.