How did you replace or get off of Seroquel/Quetiapine?

I'm grateful that Quetiapine helped me in a period when I absolutely needed better sleep. Over the course of about 2 years stabalizing anxiety levels down to what I would say is pretty normal for me, I'm down to ~12.5 mg. I don't take any other medications.

What I've tried so far:

• nothing: this is the ideal path for me, but...its back to default sleep behavior. Long time to get to sleep, wake up 3-4 hours seemingly for no reason, toss and turn for 2 hours, usually catch a good hour at the end
• melatonin: I "feel" sleepier, but essentiall same result as nothing
• magnesium glyconate and l-theanine: this somehow feels less artifical feeling than melatonin, but still doesn't seem to make an impactful difference, maybe 15% better than melatonin
• quetiapine + magnesium: this was in an random attempt to possblly "trick" myself and eventually drop the quetiapine, but ironically this combination seemed to be slightly worse than quetiapine alone

I'm not sure if I need to give any of these a longer trial period - but usually after 3-4 nights, the consequences of several nights of bad sleep seem to take over.

Any thoughts or successes you've had?