Going to bed when it’s bedtime no matter how much you’re going to toss and turn is the first step. Your body will start to realize it is the time to go to sleep eventually. It takes a while. No being on your phone or reading or anything.

You might be interested in this

https://en.m.wikipedia.org/wiki/Delayed_sleep_phase_disorder

DSPD is frequently misdiagnosed or dismissed. It has been named as one of the sleep disorders most commonly misdiagnosed as a primary psychiatric disorder. DSPD is often confused with psychophysiological insomnia; depression; psychiatric disorders such as schizophrenia, ADHD or ADD; other sleep disorders; or school refusal. Practitioners of sleep medicine point out the dismally low rate of accurate diagnosis of the disorder, and have often asked for better physician education on sleep disorders.

Maybe your body is telling you to live on the other side of the world. You'd be impervious to jet lag.

Yeah this was me for all my life until last spring. It was depression related although it's hard to say which came first. I "cured" it by getting blinds that let the sun through, by getting a cat that wakes me up every morning and by smoking a lot of weed. Milage may very much vary 😅

I have insomnia too so I feel for you, it's awful. How's your Sleep hygiene? Things like avoiding blue light (so no phones) and no caffeine after 2pmbreally help.

I also use a herbal roll on but steer well clear of lavender cos too much is a stimulant

You might be interested in trying a polyphasic sleep cycle. Instead of one big 8 hour sleep each day, you could try two 4 hour sleeps. So, you can have your middle of the night sleep, and maybe another one after you get home from work or eat dinner or something.

Supposedly polyphasic was pretty common prior to the industrial revolution. Nothing really wrong with it if your schedule can accommodate it.