Okay, recently, I've suffered pretty badly from this, and this thread made me think I should possibly write something about it.
 
Insomnia is, as most of you know is the inability to sleep. This particular affectation can cause so many varying and potentially untold effects on people, depending on the individual. I write this, partly to try and help others understand a bit more about it, despite not being an expert myself, and how it affects me, and could affect others.
 
First, some background information on me and my experiences with insomnia. I am twenty years old, and believe I have suffered with insomnia since I was approximately fourteen. At 14, I was going to bed at about 2130/2200 but not getting to sleep until between 0200 and 0330, having to get up at 0700. Now I am 20, I have no set 'getting up' time, but still try to go to bed at a consistent time, usually 0100-0200 hours. Sometimes I get to sleep at about 0500 hours. Often I stay awake all night, rarely I'll sleep within an hour of going to bed.
 
Over the years, this has had an obvious effect on me as a person. I find myself very angry throughout the day, and much calmer at night, as my body went through a seemingly unconscious sleep phase, where it rested more during the day than it did at night, owing to a lack of sleep. This, of course, meant I didn't fulfill my full potential in secondary school. (High School I believe in America), with a steady decline over the last 3 years, as my problem got worse. After one year of sixth form, I dropped out and went to college, I was 18 by this point, and of legal drinking age in the UK. Despite being in better conditions generally, I was still suffering, and going to college on ad little as two hours sleep. I quickly turned to drinking heavily. I'm talking between 3-5 cans of very strong cider every night, just in order to sleep. This meant going to college with a hangover, which obviously didn't help my situation. 
 
Now, I am in university, and my problem is the worse it has been for a long while, but still manageable. I am attended classes, and using my insomnia to polish my projects off. I have a psychiatrist in my uni town, who is on speed dial if I need them.
 
The biggest problem I have, is that the major active ingredient in all sleep aid/remedies, I am allergic to, so I will get a couple of hours sleep, but spend longer in the bathroom later. A major factor is diet, however university student's diets are limited by a strict budget, so diets are similar, the majority are lucky enough to not have a full blown issue with the affectation, and I envy them.
 
My problem is at the point where I hallucinate often, usually as a resultant depression caused by a lack of sleep. I often get to a point where I wonder why I choose to remain here. After 40+ hours no sleep, you wonder what the point is, and you question everything in your life, and you shrink down the good points, overshadow them, make mountains out of the molehills in your life.
 
Now, in some posts in sleeplessness-related threads, I speak about much more physical aspects of health affection as a result of insomnia. Fortunately, most people pass out and get sleep before this happens. Unfortunately, I cannot offer a solid cure or more robust help on the subject matter, as this depends largely on the individual.
 
All I can say is this: If you start hallucinating vividly, or feeling physically unwell through an inability to sleep not choosing not to sleep, consult your doctor.
If you start to feel depressed, don't dwell on the negatives, but focus on the positive things in your life, no matter how small.*
Try a more balanced approach to your diet, you'll be amazed at how this helps.
 
 
*I have recently dwelled up the bleakness of my life - my massive debt, how I can't get financial help, how nothing wants to go right in my life. BUT. I recently signed a contract to get a house for my next year of university study, with some friends of mine. I focused on this contract, how good it felt to have some security, no matter how small, and it helped. A lot.
 
I am almost certain this isn't as comprehensive or as helpful as I intended it to be when I started, but hey, I'm at 41 hours awake right now. Get some sleep folks, and feel better.   

Good on you for posting this Candle; it takes a lot to talk about such a serious issue.  
The reading itself was quite interesting and informative.
 
Moral of the story kids: Go to bed early!

Quite strange. Just last night I was having the same thing. Not the first time, of course. Go to bed at 21:30 or so but I didn't fall asleep until 4:00 am. Ugh.
 
Fortunately, this happens rarely. Like once in 4 days, but it happens. People blame videogames, since I tend to play all the way till it's time to sleep. Coffee doesn't have any effect, since I've slept normally in days that I've drank it. I think it's mostly because of leftover energy that should have been used up during the day. That, or problems with ones nerves, which seems like the OP's problem.

I hear ya man, ive had trouble sleeping for a long time. Insomnia just kinda happens off and on at random for me and its always hell when i get it.

I havent slept for more then 4-5 hours in the last month. Every time I try to sleep I think of all the shit I could be doing, and end up passing out doing one of those tihngs. /shrug

I had exactly the same problem at university and for a year or two after.  Im 26 now and I learnt the best ways to control it.  I was also not a fan of taking drugs to aid sleep.  I will PM you some of the tips and techniques I worked on and picked up to help me sleep.  Don't worry, you will be fine.