You need to change your environment and make sleeping pleasurable, because otherwise any will-based (self-discipline-based) measures will be short-lived and ultimately fail.

What can make sleeping pleasurable for you? Say, I listen to audiobooks when I am falling asleep. I sleep on a silk fitted sheet, have silk pillows and silk pillowcases (when I can afford it, I will buy a silk comforter), and they are very pleasant and cool to the touch. I have this bottle https://www.amazon.com/Empty-Amber-G...dp/B01G98Y1BA/ that comes with labels for hand-labeling - I dilute lavender essential oil in water and spray my silk bedding before I go to bed, and I hand-wrote "Nighttime spray" on the label in my best hand writing, so I like seeing my handwriting (I was a messy hand writer as a kid, worked on developing a pleasant handwriting as an adult, and now enjoy seeing how I handwrite).

I in no way suggest that you replicate my habits, but just that the way to sleeping regularly is by being hedonistic about it - as opposed to, well, punitive. Spend some time figuring out what it is that will make sleeping something that you look forward to. Say, I look forward to audiobooks and the smell of lavender. Again, do not want to impose specific advice on you, but suggest the general methodology instead.