Happy Light for the win! And vitamin D, however you can come by it. https://sleepyheadcentral.com/light-therapy-hacks-to-reset-your-circadian-rhythms-for-seasonal-affective-disorder-circadian-rhythms-sleep-disorders/

Remember to check UVB versus UVA on devices as some things are unfortunately vague about it.

UVB is the good stuff, but it's blocked by almost all glass. Light might provide UVB but if it's encased in glass of some sort, you'll get zero of the good stuff and all of the dangerous UVA.

Same for your home windows: That sunlight feeling is all just placebo (which is valid! Just not the vitamins you want long-term).

Best of luck in the dark cycle.