I have anxious habit to play in hair . dry scalp , trying to quit. picked dandruff , scab . picked at scab & feels moist , what's that moistness?

Manage it: You won't be able to stop, so don't be hard on yourself. Some folks are wired to do this kind of thing with scalp lesions. What you can do is manage any dandruff / seborrheic dermatitis aggressively; perhaps ketoconazole would be right for you in addition to a good dandruff shampoo, and you can ask your physician about coal tar, sulfur, selenium, and/or a bit of a glucocorticoid.