I'm not going to lie -- it hurts

We've come to the end of spring break week. It's been good, better organized than I thought it would end up being, and only so because my parents have stepped in to help me handle having both Lil E and work full-time this week.
The Ex was supposed to have Lil E all week. It is in our parenting agreement, but he either forgot or ignored it. This time, rather than remind him or ask him what his plans are, I let it be.
I am extricating myself, slowly and surely, from being that person in his life. Instead, I prepared to have Lil E at home with me. Or rather, to have him at the Shedd Aquarium with me, on my lap chatting away about the young Obi Wan Kenobi while I posted on probiotics, with my parents at Brookfield Zoo, and today, happily baking Easter goodies in my mother's kitchen. The Ex took him golfing for his part, and not a word was said of the lacking week of extra visitation time. I'd taken my step back, and even with all the arrangements that had to be made, it was good to have that little voice chattering away in the house for more hours this week.
Changing the schedule, whether from school to vacation or from home to visitation, is hard on all of us, though. It shows up in those tantrumy moments, in the small child going completely limp in a sobbing heap because I've dictated unfairly that he can only bring three stuffed animal babies to the grocery store or Grandma's house or down to get the laundry from the dryer.
It shows up in the eye-to-eye talks when I remind him (again) that he cannot tell Mommy no when I tell him to do something, that stomping on feet or hitting or sticking out his tongue is in no way acceptable, that there are other ways to work out the frustration than screaming.