Energy is like income, a checkbook, your IQ. You don't have the same as everyone else, and you're not supposed to.
And you have different energies available for different things.
When energy gets low you can experience stress. Then stress uses up more energy. Lower energy leads to more stress and less energy and more stress. It's a rotten little circle.
God may give you less energy in some areas so that you won't focus on areas where he doesn't want you.
If you do mis-focus, you run out of gas to force you back to where you should be.
You know those times when you're going hard but you're not tired and you feel like you could go on forever?
Maybe that's your true north.