Sounds a lot like dermatillomania. There's a section on here for that, where you could likely get better answers. I've never tried to get evaluated for it, or anything but i've been a scab picker nearly all my life (worse when you have eczema!). I think some people say its a nervous habit, others a form of compulsion, a source of comfort. I think its a bit of compulsion for me as I don't like the uneven feel on my skin as it scabs, so I pick it, and it opens the wound and then it scabs over and I am too impatient to allow it to heal or my hand brushes across it and then I have to pick it.

When I was 13/14, my dermatologist would tell my mother to put gloves on my hands during bedtime to deter my scratching and picking in my sleep. Perhaps you could try something similar to block your fingers in the daytime (when not in public). It's not as bad now, but I do still pick certain areas.

One source of advice I did find helpful in minimizing the scars was to select only one area (though I had to choose like three) to pick and then ignore the other scabs. Like, you allow yourself to pick those areas but limit the picking to there so that your need is satisfied and you're not destroying your arms/legs, etc.