Note the follow up that sticking to your bedtime 4 times in a row is another goal. We’re ruined, folks.
Hell, if I get anything over 7 hours my lower back hates me for the first hour after I get up. My ideal right now, is about 6 hours, and I typically wake up naturally after about that. Unless I’m very tired.
You might need a new a different bed. That and exercising regularly completely killed my lower back pain.