I'm just someone on the internet, take everything with a grain of salt.

Only go to sleep when you really intent to. No scrolling on your phone in the bed, no reading books,...

The moment you lay/sit down, you intent to sleep.

If it doesn't work: get up, do something else, try again later.

Isolate factors that could keep you awake like sugar, caffeine, alkohol,... Even a handfull of gummies could influence when you fall asleep.

Check on air-quality, room temperature and moisture, dryness of bedding, room -brightness, -light sources, noice levels.

Try out keeping a journal of these things, as well as your mental state and reflect on your sleep in the morning.

If available, ask your SO or room-mate about their sleep, that's a great way to identify external influences.

If your data stays inconsistent, ask a doctor, as there might be medical conditions influencing you falling asleep, ike high blood pressure or hormone imbalances.