god damn thats gonna be tough.
It's the most powerful and natural way to challenge your problem.
Comparatively speaking, everybody else in this thread is talking pissant shite compared to what I said (no offence intended). It's shocking to me that only I have mentioned it - particularly after you responded to me. That's just how ubiquitous using caffeine and stimulant drugs is. Nobody even thinks "wait a minute, maybe it's the fact I drug myself with drugs that keep people awake, every day".
Smoking weed, trying to adjust your light to invoke some circadian rhythm response.. all very minor/rubbish solutions IF you are experiencing this problem and have not yet tried to come completely off caffeine and stimulants.
I remember buying a coffee machine from a fella about a decade ago and him telling me he could no longer drink it and I thought, fuck, what a nightmare. Well, about 5 years ago, I became that fella. I didnt' have problems with insomnia - I had problems where I would be royally fucked after having strong coffee, after the first hour. I have no idea what the situation is with my body but it just makes it very clear to me, no more strong coffee. I quite caffeine for a year or two andt hen slowly introduced only green tea and the odd instant at night.
And the results are fucking great. I am never tired during the day. I never struggle to go to sleep. I have stable energy all the time. It's a thousand times better.