sleep help

What are your most reliable sleep aids for insomnia? Exhausted doesn't even begin to describe how I feel every night but I lay in bed for hours with my eyes closed and just can't go to sleep. There aren't any external causes (no TV or anything like that on and we have blackout curtains). My doctor says to take unisom or benadryl but I'd like to avoid medications if possible

*thanks I'm still trying to find something that works. my biggest problem is when my son wakes up at 3AM and then I can't go back to sleep, even if he's only up for a minute