communication with my ex

I have been divorced for a year and separated for 2. I have two beautiful children. Unfortunately this means that I am forever connected to the S.O.B. My problem (one of them) is that we are suppose to use a communication book to relay info about the kids. Of course he used it as a tool to belittle and criticize me, the way I parent and how I am "emotionally abusing" my kids, talk about projection. I stopped reading these letters, much to his annoyance, but he is now finding other ways to control me, through the children. i am doing my best to leave them out of it and not discuss anything that he does, but as a true narcissist he continues to tell the kids things he shouldn't all the while making himself out to be the victim and everything is my fault.
There are things that need to be talked about with the kids, but I have no idea how to do this, all attempts in the past have failed. He takes the kids to a councellor who believes that he is hurt and acting out from that hurt, so he's got her won over. I would love any advice. It is like talking to a brick wall, everything is twisted to be my fault, and in his reality everything I say is a strategic plan, for what I don't know.
I didn't go through the history of the marriage, it's been said before, I have grown alot over the last 2 years, but feel that I may be back sliding because of his incessant obsession with making my life a misery. Oh and he is a member of law enforcement which makes everything that little bit harder!