I dealt with dermatillomania since I was a very young child, up until about two years ago. I'm 33 now, so a long time. I can safely say now that I have broken free of it. I have been working on coping skills and stuff like that for years to deal with bipolar, I think it spilled over and helped me with the picking. Also mindfulness. Really paying attention to the urge and forcing myself to do something else, being aware of what I was feeling and why. It was a long process but I did get there eventually. I still have the urges, but I have learned how to recognize them and how to deal with them more appropriately.

I hope you can find something that helps you, have you ever tried mindful meditation? I'd check it out if you haven't. I know it's such a hard thing to stop and very misunderstood.