I have had sleeping troubles since I could remember. Even as a little kid. I'd lay there in the dark and have conversations with my stuffed animals.
What I've been doing lately is the best thing I've found so far to trick myself into falling sleep.
First of all, I stay up as late as I possibly can. Probably not a good thing. I definitely haven't been getting enough sleep. However, I think the rest of what I do would still work pretty well without doing that, I just get too involved in what I'm doing to make myself go to bed.
I stopped sleeping in my bed, and instead lay down on the couch. I turn on the tv to something completely boring like the 24/7 local news channel, turn it on mute when I know I'm getting close to sleep, and turn on white noise on my laptop. I use iserenity.com. I actually use 4 different white noises open in different tabs. I have them all saved to a folder in my bookmarks, and just select "open all tabs", and they all open at once. Then I play really "boring" games while laying there, usually Hearts. Soon it becomes too hard to keep my eyes open, so I turn over and usually fall right asleep. It's kind of like tricking myself into thinking that it's not actually time to go to sleep. If I go lay down in bed, my mind just races a mile a minute. Always has. So I try not to give myself the chance to do that. I've always been a champion at falling asleep at random times during the day when things are going on around me, but as soon as it's "time to sleep", I can't do it. So for me it was all about tricking my brain to NOT think "it's time to go to sleep", if that makes sense.
Another big thing was NOT having to get up and go to work in the morning, which always gave me a lot more anxiety about falling asleep the night before. I know that often can't be helped, but it made a big difference for me. Then again, now I'm just woken up early by a toddler, but I don't get anxiety about that. If you really aren't getting the sleep you need and have any possible way to switch jobs to something that has a swing shift option, that might be worthwhile. Good luck!