I am glad things are going well and you are getting some time to yourself to recharge. I know that when I become a cranky mommy it means I need a break. It's good you asked for that time from your ex and he is giving it to you.
As far as the CS, I know in my state it's nothing more than a formula and it is non-negotialble unless you have other assest or money situation that needs to be taken into consideration. The formula figures in salaries, and parenting time and household and related expenses. But it is pretty much a mathematical equation. I am sure your layer or mediator can make that kind of cut and dry for the both of you.
I hope everything goes as smoothly as possible for you and you can have that closure.
