Just a suggestion... I take Melatonin shortly before I go to bed, and if that doesn't have me drifting off within a half hour, I take the over the counter sleep med (just watch the packaging, you don't want the one with diphenhydramine, you want the one with doxylamine). Generally works for me, however I've built up quite a tolerance to it so I now have a prescription for ambien, as well.
Also, really try to set up a routine for when you go to bed. ie, q nice hot bath, read a couple chapters, warm milk or hot chocolate (even better with a little splash of baileys' in it)....
Make sure your room is quiet, perhaps a little white noise if you're used to daytime sounds. I personally sleep with the TV on low volume and turn on a program I've seen a billion and one times so I'm not all that interested.
And if you have kids.....Good Luck! They need a stron reminder that bedtime is bedtime! Even just telling them they must be in bed reading or whatever, it MUST be peaceful so you can sleep.
And most of all, GOOD LUCK!!!
Jen911