Two more cents - I have my own negative coping technique which I continue to battle so I can relate. One thing my T told me, when I related that sometimes my 'acting out' feels unstoppable like a drug addiction, was that our brains actually start producing chemicals (dopamine? cant remember the name) in anticipation of acting out and so resistance seems unstoppable once we start letting ourselves just think about the acting out - knowing thats what is chemically occurring has helped me divert/distract myself from the acting out.
And, sorry, but I agree with the other replies, it is very likely related to your abuse history. It's frustrating how many ways childhood sexual abuse infects our lives. The fact that you're in therapy is a strong indicator you are making progress and have courage to face these issues.
I have to survive and I hope to thrive.
Alumni Dahlonega WoR May 2010
Alumni Sequoia WoR March 2012