When it isn't going to work out

Unfortunately for me and my kids, it isn't going to work out. I have resigned myself to this fact and now just trying to make sure things are in place for me after the divorce to allow me the emotional, physical and financial resources to finish the job of parenting. It would be very helpful to hear from others on this website about advice you would give to someone like me. My spouse's perspective (ADD spouse) on his contributions financially and parenting are not the same as mine. As I near the time for final agreement for divorce I have accepted the fact that I will STILL be the one to be coordinating all the facets of the kids lives and sacrificing my time and energy while he does what best suits him. He doesn't have the $ resources to make this an easier job for me, in fact I make more than him. But at the same time he is demanding things that don't seem fair given what I have contributed in the past, what I still contribute and what I am likely to contribute in the future. How can I protect my sanity so I can have a life eventually after so many years of taking on too many burdens due to a partner with ADD? I can't continue to have this extra child, demanding more than I have. So depleted......