I'm with you - I have a few hits of some low-grade stuff maybe an hour or two before bed, and then I doze off naturally when it's dark out.
i also eat well, and make sure to not have blue light exposure for the last hour of my day.
But what really helped me, especially since I have crazy ADHD, is exercise. I lift when I get up, and do 1-2 hours of hard HIIT in the evenings after work. My body is absolutely shot by the time I'm done so I really don't have the energy to have my brain go all over the place. This coupled with a nice cold plunge in the evenings after said workouts (and another cold shower before I sleep), and good nutrition has helped me big time.
The THC does help, especially if I do it at the right time. If I smoke in the afternoons I am absolutely destroyed by sundown. I do fear it's creating an addiction or a physical dependence, but I value my sleep considerably.