Hi Rouky, I too find life much easier when there is no contact with XH. And luckily in my case he seems completely disinterested in contacting me, so life is pretty peaceful. Of course when you have children together there's a degree of contact and in time, I imagine that sting will fade.
As for the changing of plans, I can understand your point of view on this. I think it is fine to say no when you aren't available to help and have other plans. I guess the thing to watch out for is your own understandable anger about the whole situation and the care of your kids being the focus of that.
In XH's case, we had a good R with his XW and would help when we can. Of course there were times when we couldn't too. I would say, make plans for you when the kids aren't with you and if it isn't convenient to change them, don't. However, there may be times when you can be flexible if asked too.
JMHO of course, and I think you are doing well. There is always hope in the longer term if the door is open a crack at your end. However, please don't put your own life on hold in any way, shape or form. If your H wants you back, you will have travelled a long way forwards and he will have some serious work to do.
Xx
T 13 M 7 Me 48 H 46 SS 15 BD 7.14 PA D final 5.16 (H filed)
We receive & we lose, and must try to achieve gratitude & embrace with whole hearts whatever of life that remains after the losses - Dubus