Awake at 3 a.m.? Deepest sympathy. MUST be asleep before 3 a.m. or truly an entire night is lost. For a decent buffer before the next day, have to sleep at least four hours, e.g., 1 to 5 or 2 to 6 a.m. A full eight hours is best.
But you know that. Everyone knows that. Just as everyone knows we can shortchange our sleep a couple days, but eventually we have to catch up on sleep or stay run down.
What was the topic again? (wander wander) Oh yeah, how to get to sleep. Think happy thoughts. Recall pleasant times, and with luck you'll soon be snoozing and reliving some of the best times, often with fun new variations. As the advice goes, Stay In Control, including of your sleep. Seriously.
