I didn’t love feeling drained at the end of the day when I crashed

That can be eliminated completely: Don't let the loss of appetite fool you, eat by exact calorie count & clock, against all instincts. Don't take it in the morning without enough food either. After anything that would require a rest otherwise, such as a long walk, even after lunch when you didn't have enough sleep at night, certainly after a workout, take as much rest as you'd normally need, even when you don't feel like it. Even 20 minutes cleaning, 10 minutes rest; don't go into a cleaning frenzy.

It goes to zero. (Experiences may vary, but I went from crashing after 3 - 4 hours to no crashes at all, being happy and productive after 14 minutes awake, then fall asleep instantly.)