Body-focused repetitive behaviours like skin picking often operate just below the level of conscious awareness. The urge can build quietly during moments of stress or boredom, and the temporary relief it brings makes the pattern harder to interrupt. Many people feel significant shame about it, which tends to increase the emotional weight that drives the behaviour in the first place.
Therapy starts by bringing the automatic into view: noticing the triggers, the sensations, the emotional states that come before the urge. From there, you can work on developing alternative responses that address the same underlying need without the harm. This often includes habit reversal strategies, ways to manage the emotions that escalate the urge, and a more accurate understanding of why the behaviour developed, so you are not working against yourself in trying to change it.