Like samurai, I suffered from varying degrees of insomnia for most of my adult life. I am now sleeping 7 hours decent sleep per night and haven't had a prescription in 2 years.
Most advice is quite subjective, but worth trying anyway. For me, it was a combination of:
CBT - helped break the cycle of drugs/sleep/drugs/sleep more than anything else, but was also massively beneficial from a mental control and general self awareness perspective
Moving everything out of my bedroom - no books, no tv, no clocks. The alarm on my mobile phone is now face down on the other side of the room. If I can't see the time, I'm less likely to worry about it.
Booze - any alcohol midweek was detrimental to good sleep for me, so it had to go, but has returned to an extent now.
Perspective - as samurai pointed out, one of the key things for me was the cycle your brain goes into when you are aware that it's 3am and you're still awake and catching a train in 4 hours. It took a long time, but now I just think "who cares, I've managed with less sleep plenty of times, i'll be fine tomorrow"
If this is a short term problem, I can wholeheartedly recommend Zopiclone as a drug to help you sleep. After years on benzos, it was a welcome relief to have something which wouldn't leave me feeling like i'd been hit by a train in the morning. Avoid drugs entirely if this seems like something that will not go away in a couple of weeks. If you think trying to get to sleep now is bad, just wait until you try to get to sleep after weeks/months/years of taking benzos. And believe me, your GP will happily prescribe them.