Delphine: boy, oh boy, do I know exactly what you just wrote! I work on detaching from this anger all the time.
My very first therapist, post divorce, 8-9 years ago told me, "he will always try to hurt you, and he will use the children to do it". She really knew what she was talking about!
I will be totally calm, together, loving life and then BOOM, another legal thing, another lie, another manilpulation with the children, another email trying to GET something out of me (which now means time with children...). Such a mess. Yes, I can be calm and together with my ex (very smart, by the way) and then later, it hits....damnit! He did it again!!!
How do I deal? Well, I work at it every day. I practice very hard at releasing his energy, because I know I not only feel it, but had a long habit of holding onto it (many years of a habit is hard to break)
So I use visualization and breathing to clear it out of me. Some days it's an all day long thing! I try to only hang on to my own energy...I feel for those I care about (my children, friends and family) but my best bet, even with them, is to let go of any negativity I may hold, even thiers. a little example: my son just realized a huge conflict coming up.....an extremely important jazz festival out of state and his girlfriend's prom night. He was so upset. I felt his frustration (hard to miss!) but even he needs to feel this and then deal....so how helpful would it be for me to focus and dwell on how much that sucks? No solutions ever come from focusing on what is going "wrong". So we decided, yes, this is a drag, but lets not dispair, let it sit a bit and we will find a solution.
Ok, so much easier to do with someone you love, no? In this way, though, I help my son. I don't care if I help my ex, and certainly don't share what I do with him, this is to help ME!
This is, in a nutshell, what I do.
I identify what hurts me and say it! Then I visualize it clearing out of my body (I use a toilet flushing image frequently!!!) sending it down my spine, to the center of the earth, where it (negative energy) turns back into love or goes back to it's owner (HIM). Then I focus on how I want to feel......imagining I already have that in my life and feel how happy I could be (no fear of him, a peaceful home, life with my fiance, etc).
It may sound airy fairy, but what the hell.......on this board, everyone knows how the N's effect our energy (read any post) in a negative way....
so why not take the bull by the horns and TAKE CONTROL and stop being victims of the N's and decide to CHANGE our own inner energy.
I am getting better all the time with this. Does this stop him? NO. It actually makes him madder and madder, and soon, I hope he will just implode! In the meantime, I could give a damn how he feels, and I will happily move on with my day. Screw him. He doesn't get to decide if I'm happy or not!
However, another thing I felt, reading your post, was if you can expose his lies, and you can release any of this negative enegy (that he will certainly dump on you) while you expose him, then even if you break even (as in no money earned) it would be a worthy exercise in power for you, and an example for your child. But the example has to be worth it.
For me, it was, as my children could see that even though he won a case against my relocating with them, my own convictions about what a woman should be able to do in this life were demonstrated to them. (even if the "system" supports a screwed up philosophy). Only you can decide what things are worth. I wouldn't go for the fight, however, unless you know what to do with the negativity. I didn't during the trial, and I believe my anger could very well have cost me my freedom to move.....but the good news is, real freedom is in my mind and body.....and he can't imprison me there without my consent. I guess I had to lose the case to find that out! Not a horrible trade, really.