I'm just so sorry for the torment you suffer at the hands of this crazy, crazy man.
I wish I had some advice, but I have never been in this position and have no real experience to share. I suppose I do agree with Lexie, though...
You give in to his demands--the abuse and harassment continue.
You don't give in to his demands--the abuse and harassment continue.
I wish I could tell you that I think the harassment will end if you do what he wants, but I don't think it will.
The difference, as I see it, is that if you don't give in to his demands, you keep the ground you have gained when you finally agreed to the custody and visitation plan. The black and white of the public court documents, as well as all the written evidence of the current round of harassment, has the potential to 'move the ball forward' for you and your girls. Even if just a little bit.
Ultimately, it is up to you. You are the only one who knows how much you can take on any given day. I hope and pray that things will improve very soon for you and your girls.