I struggled with this for decades and ended up noticing a pattern with the food I ate for dinners that were high in glutamates. Glutamate is an excitatory neurotransmitter and thus if you are sensitive it will put your brain into overdrive and sleep is just not possible as basically you are drugged. Only effects a small portion of the population but I can tell you, I sleep very well now that I avoid high glutamate foods past 5pm as they tend to not make my mind race until several hours after consumption and once the effect kicks in, it does not wain off until 3-5am which kills my sleep. Avoiding glutamate has been the single biggest quality of life improvement along with focusing on my gut biome which when out of balance can make it harder to fall asleep as believe it or not, out guts make a lot of the neurotransmitters we need to function including melatonin which is the sleep neurotransmitters.

I wish you luck no matter the root cause. Feel free to ask me more about this.