How do I ACTUALLY get restful sleep?

Im a man in my early 20s, and I genuinely dont think ive had what I would call a "restful" sleep since like high-school, and im really trying to figure out how to get that feeling back. These days I set aside ATLEAST 7-9 hours every night for sleep, so I know its not necessarily a time/length issue. Half of the time I sleep the entirety of the time, waking up feeling groggy and generally tired out of my mind, and the other half of the time I wake up at 2-3 am and then fall back asleep like an hour later. I dont really drink that much caffeine either.

I stopped using the TV to fall asleep, instead opting for audio books, I keep my room cold so I dont overheat while sleeping, and I workout consistently.

Ive tried all those "how to get good sleep" tips/methods and have adjusted my nightly routine to match them, however it still just doesn't fix the issue.

How do I ACTUALLY get restful sleep? What adjustments can I make? What things can I add into my routine? Is this something I should look to get medication for? Ive tried melatonin but all it does is make me sleep through my alarms and feel like a zombie the next day.