@fadeaway Speaking as a late 30s, full time working mom of 4, a lot of this ultimately can become routine, ie, not difficult because you don't have to think about it. You just do it.
That said, control what you can. During times where my schedule is too crazy to permit exercise, I count calories. At least I can maintain a healthy weight, even if I am not able to get to the gym. Likewise, I can eat well and prioritize sleep.
Lately, trips to the gym for weight lifting aren't feasible. So I'm running on a treadmill, hiking or jogging around the neighborhood (it's hilly), doing body weight, dumbbell, and core exercises
when I can.
No one is perfect, but I've been able to maintain a healthy weight for most of my adult life by just doing the best I can and being mindful. A major exception was when my thyroid went out of whack a few years ago, but that's under control now, fortunately.