Rant: Different parenting styles are driving me INSANE

My ex lets our kids (4, 7) eat cereal for dinner half the time and I'm out here meal prepping. She doesn't enforce bedtime and they come to me exhausted. I feel like I'm picking up the slack every other week and it's EXHAUSTING. We've talked about consistency a million times and nothing changes. How do you not pull your hair out over this? I know I can't control what happens at her house but it's so frustrating when they show up wrecked.