Any suggestions for precise affirmations to get myself into the habit of getting ready for bed in time and going to sleep on time?

I think I've messed up going to sleep on time (not just go to bed on time) and getting ready for bed in time for so long that I'm having trouble getting myself into the habit of doing so.

I don't want to spontaneously fall asleep in the wrong context or uncontrollably fall asleep, and I get uncontrollably talky from sleep deprivation and stuck on my phone and laptop which messes with my perception of time.