So here is the problem with insomnia...Trying to figure out what the underlying issues are, while at the same time feeling worse and worse each day due to lack of sleep.
I'm not a doctor. However I spent a good 15 years without having a good night's sleep until someone finally prescribed me something that worked. My case is different in that my issues were brought on by migraines that started when I was 19. Somehow it messed with the sleep circuitry as well. If doctors understood why this happens then maybe I would as well, but nothing's worse than having someone tell you it's all in your head, so just go count some sheep.
So while my case may be different I can claim a good bit of knowledge from the 15 years of traditional professional advice. First, medical science still doesn't even understand why we need sleep. It's a mysterious function we know is needed but not really sure why. As a result, opinions will vary greatly on what the best solution is. And what works for one person may not work for another. I had 3 different experts tell me I needed a cpap machine. "Why", I asked, "Is it going to work this time when it failed the previous two times?" Normally a blank stare follows. I've come to the conclusion that it's what they tell people when they don't know what else to do. Anyhoo...
Taming racing thoughts in a quiet bedroom can be maddening. So, maybe you do finally fall asleep, and then wake up at 3am. At which point the racing thoughts that had been hiding under the bed all the sudden come back with a flurry. Next thing you know you've stared at the ceiling for 3 hours, and now it's time to get ready for work. Good times.
One night I awoke up on nature's business, and the bedroom door stuck a little in the frame. In the short time it took before I crawled back into bed I had gone through a progression of thoughts where all the sudden I was in a panic that the foundation needed to be repaired and was recalculating my whole retirement plan. Sounds ridiculous, but nothing fills a quiet room like a noisy mind.
My best suggestion is to try everything, after resetting with a few good nights sleep from some non-addictive helpers. Take Diphenhydramine (Benadryl) or Doxylamine Succinate (The stuff they put in Nyquil to conk you out) for a few nights until you've banked a couple of good nights sleep. It's important to break the cycle, because once you start being unable to sleep, just the fear of not sleeping alone is enough to bring on panic. Once you can calm those nerves down you can concentrate on the rest.
These are normally more effective than natural supplements such as Melatonin, although for some it's effective. If you're going to use Melatonin, get the timed-release version so that you get it distributed throughout the night and not just a big dose up front.
Now try again with some of the non-medical techniques. Sleep hygiene is very important along with the nightly ritual before falling asleep. You can look up what all constitutes sleep hygiene, but one new item to this list is to avoid iPads, phones, etc, before trying to fall asleep. The light from the screen can really mess with areas of the brain that are tuned to track the day/night cycle. This doesn't bother some people, but for people having issues it's something to cut out.
Getting good exercise early in the day is vital. Don't exercise though after 7 or 8pm since it's takes the body a while to rev back down.
Best is to read a book until you can't keep your eyes open and falling asleep. Then hit the lights and let sleep take over. Reading is about the best way to tame thoughts and focus on something relaxing. On that note, it's best to read fiction/fantasy/sci-fi or anything that takes you away from the real world into another one. Reading a book on current events or politics or anything that may get you emotional over something defeats the purpose (yes that includes Longhorn news which at times can be frustrating
So maybe that helps you fall asleep, but what happens when you wake up at 3am. Do you read more?...Maybe. If that works then great. Although by turning the light back on that can have a deleterious effect and could just result in reading for 3 hours.
Here's a trick I came across by accident but helps me immensely: First you buy a cheap MP3 player, but one with a LED screen that shows in the dark. I have a SanDisk Sansa Clip. It's important this not be an iPod or some other overly bright screen. Second you need to buy an audio book designed for calming techniques or self-hypnosis. If found this in the library and it works for me:
http://www.amazon.com/Sleep-Medical-Self-Hypnosis-Steven-Gurgevich/dp/1591797144
Rip the CD to the MP3 player and at 3am when you don't want to turn on the light for a book, put a headphone in one ear and start listening.
I found it impossible to learn calming techniques, yoga, or anything else during the day that I could successfully use at night without aids when the brain is in full spin cycle. By having this in my ear and coaching in the middle of the night is the only way I could find to actually relax.
Now I have no idea whether I'm accomplishing self-hypnosis or not. It could be any book with a calming voice that allows you to focus on it. For all I know it could work reading out cake recipes, but having such a focal point in your ear can drown out the noise.
As for the rest, try everything that's recommended; although do a little Googling first to see if there are any potential negative effects. For instance drinking a glass of wine at night is great for relaxing, but alcohol can actually interfere with sleep cycles, making the sleep not as productive. However it works for a lot of people, so give it a shot. Some people do well with warm milk, or a glass of hot tea (no caffeine of course). All of these are designed to relax before trying to sleep.
If you have tried all of the non-medicinal techniques and still are unable to get a handle, then it may be time for some doctors and prescriptions. Most will try to handle underlying issues first (such as depression or other psychological problems). Some may go straight for the knockout pill. This is a tricky route, because once you rely on prescription meds to sleep you will ALWAYS rely on them to sleep. Most of them develop some type of reliance and getting off can be very difficult.
Sounds like you have a temporary thing to work out, maybe a life issue that will pass. I'd definitely start by going with all the traditional suggestions, work on sleep hygiene and a set go-to-sleep/wake-up schedule first.
Maybe just reading this incredibly long post is enough to make you fall asleep

Did I mention I have a problem sleeping sometimes?...
Either way, good luck! Feel free to PM me if I hit a spot you may want more info on.