I'm sorry to hear that you are struggling with this habit. I personally don't know a lot of about skin picking, but I do believe that is does fall in the SH category as well. You might post a thread in the SH forum here:
Self Injury - Forums at Psych Central There are likely many members that have struggled with something similar that can give you advice on how to break the habit. Sorry I coulndnt be more help to you. I hope you find the answers you are looking for.