If I were you, I'd think about getting a checkup. Or at least I'd sit down and think (without falling asleep in the chair) about what I've eaten in the last week, what I've done differently, what I haven't done.
You have good energy when you're not ill or overtired, and when you have enough calories inside you (most of us have no trouble with that) to run on.
That being said, it certainly takes my body a while to adjust to a new schedule - sometimes as long as a week or two. If you fell asleep on your own very early, your body must have needed the rest! But try to keep more or less to the schedule you want to set, and eventually it will seem right.