I don't finger pick, but I do chew my lip. What helps for me is when I catch myself doing it, it's a sign that I'm tired and need to rest, or that I need to do some mindfulness practices. Which is like distracting yourself, but paying full attention to yourself while you're doing it.

For the overnight picking, could you maybe wear some light cotton gloves? If you slap some moisturiser on beforehand you'll get the added benefit of an overnight beauty treatment.