Studies I have seen suggest that any sleep aid, any at all, will lose its oomph over time and with exposure to it. So, if you can, use at least two DIFFERENT sleep aids, and try to go without them as much as you can stand.

I have short sleep. The quality when I sleep is good, just not long enough. So, when I need a catch-up, I take no more than 5 mg of melatonin maybe once, at most twice, weekly. I tough it out the other days. This way, it keeps melatonin potent.

I have heard that chamomile tea helps at bed time, and it's worth a shot.

Taking 200 mg of magnesium salt (citrate, malate, taurate, bis-glycinate...) about an hour before bed is also a bit of an aid, and it can help to calm a jumpy heart.