Anyone tried CBD/CBN Tincture for insomnia?

Has anyone had success with CBD/CBN Tincture for insomnia? If so, what dose works for you and how late can it be taken to avoid daytime drowsiness? I've had severe insomnia for over a year and wake often during the night, usually unable to go back to sleep after 5:00am. I bought some tincture that has 10mg each of CBD and CBN from hemp, but I'm afraid to try it, wondering now if it's safe. I've tried sleep restriction therapy and had a sleep study done. The only med my doctor will prescribe is Trazodone, which doesn't always work (100-150mg/night). She also suggested Melatonin. I'm only taking 2mg but since it gives me very vivid dreams I think it interferes with deep sleep.