Hey, I have the same problem..and I have had it since I was a kid. I have horrible scars now because of it. I finally got myself to stop.. I have to wear long sleeve shirts and long pants when I have a scab -- or else I will pick it. But, it helps me forget it is there. Also, think of the scarring it is going to leave...and just tell yourself, "I HAVE CONTROL OF MYSELF" and "my scabs don't have control of me"
It is such a hard habit to break but once one scar turns into two...two turn into 3, and three turn into 12.. You realize you HAVE to stop or you could permanently disfigure yourself.
I have so many scars from this...and now that I have stopped, I am trying to get rid of the scars... which is not an easy feat.
Good luck, ,, and if all else fails, go to counseling. They can help you with "behavior modification".