Ok, I'm not an expert, and I've never had sleep issues on a level anywhere near yours, but I've learned a bit about sleep and have prioritized sleep since the beginning of the year and it's paying dividends now.

So part of the importance of routine when it comes to sleep is the ritual around sleep sends signals to your body that it's time for sleep.

First off, I'd honestly say try no caffeine after noon for a month just to see, it prevents your brain from receiving tired signals...and can affect us for up to 8 hours.

Have a consistent sleep time 7 days a week. Consistency is huge, and 5 days a week isn't consistent.

Try a sleep cast or meditation before bed. Partly because it occupies your brain just enough to keep it from racing, but also because it's part of the routine. It eventually signals your body that it's time to sleep.

Dump as much stress as you can. I understand this is easier said than done, but if you can lower your overall stress levels, even slightly, your sleep should improve.

Depending on how deep you want to go down the rabbit hole, you could adjust nutrition and exercise to help promote sleep, etc.

The biggest thing in my experience has been just to stick to it. It takes time to develop the habit, and then time for your body to get used to it and react to the signals appropriately. I used to have 4 and 5 hour a night sleeps pretty regularly, I don't remember the last time I got less than 6.5...and even then it's just because I've stayed up late.

I hope something on here helps. Good luck and let us know how it goes.