is it because of BPD or something seperate?

hi, i've been skin picking since i was a very young child but have never told my care team about it. I've been diagnosed with Borderline Personality disorder 4 years ago and im wondering if the skin picking is part of this disorder or if its an impulse control disorder? can you have both? i dont really know why i do it, i suppose i could have started as a child due to my unstable home life. But im not currently under any major stress and although i do suffer with anxiety, i dont actually always do it when im anxious. I really dont feel im able to stop this at the moment. I'm already on medications that should help, but they dont. any ideas?