I had severe insomnia for 3 years where it would take me well over three hours of laying in bed at night to fall asleep. Once, I laid in bed at 8pm and didn't fall asleep until 2am. It was absolutely hopeless even trying to go to bed early. I tried all of the non-medication ways to go to sleep faster but nothing worked.
Valerian Root supplements worked pretty well for me. I also downloaded this thing for my computer that changes the color tint to an orangey/sunset color at night (it's really not noticeable at all, you notice it when it first changes but then get used to it). It's supposed to help because the "blue light" that normally comes from the computer at night tends to wake up your brain more (it reminds you of the sky during the day).
Also be sure to keep your bedroom completely dark at night.
These worked well to have me fall asleep within 30 minutes. Then I got put on Seroquel for my Bipolar II Disorder and I take it about an hour before I want to go to sleep. I'm pretty much knocked out as soon as I lay in bed and pray. I don't take the Valerian Root with it of course, I did on my first night (I didn't realize Seroquel was almost like a sleeping pill) and then it took me 20 minutes to wake up the next morning and I felt like a zombie all day. Of course it could've just been the startup effects of the Seroquel though.
I noticed your username; since you have Bipolar Disorder, have you ever tried Seroquel? Don't take it just by my advice though, definitely talk to your psychiatrist or doctor first. Seroquel tends to turn you into an exhausted zombie for the first couple weeks, and I noticed a lot more daytime tiredness when I was on XR then regular. Now that I'm stabilized on regular Seroquel, though, it pretty much just acts as a sleep aid and doesn't really detract from my energy throughout the day.
Good luck with everything!