I have the same issue. This is why I feel like this for most of the day.

Literally me everyday

Not enough sleep? Tired.
Too much sleep? You guessed it, still tired
Just the right amo–yeah that doesn’t happen lol

Same. How does one fix this? I’ve had this issue for years.

You might have undiagnosed ADHD, I’m serious.

If you can, get that checked out (which can be really hard for adults, depends a lot on where you live).

I’d talk to a psychologist, not bring it up immediately but mention all symptoms messing with my day to day life.

Half of the day, it’s melatonin time, the other half of the day, it’s caffeine time

Get checked for sleep apnea. It’s a very serious condition that causes you to stop breathing when you’re asleep. Most of the time you’ll wake up coughing. But there’s a chance you’ll never wake up again.

If you snore, get it checked out.