So for a long time, I had a habit of sleeping at 3 or 4 am, and would wake up at 8 for work. I would then take a long nap around the evening once I got back home. Sleeping at 11 or 12 at night felt alien to me, and never happened no matter how much I tried it.
Now, 3 weeks ago, I was in a situation where I was not able to take my evening naps. Missed 3 naps, and on the fourth day I was so tired, I was dosing off around 8 pm. The sleep pressure was so intense, that I was asleep around 11. I had a night awakening, but when I woke up again at 8am, I had never felt better in the morning. I wasnt at 100%, but significantly feeling better.
I also started taking 0.2 mg melatonin(a tiny bite from a 2mg pill).
The one lesson I learned from this experience, is that if you want to sleep early, you have to find a way to increase your sleep pressure early at night, and sleep deprivation for a few days can help with this. I know this might not be the most 'ideal' way of fixing your sleep, but it certainly helped me.
Also, no caffeine after 6pm helped as well😃