best advice i can give you all is this.
if you don't know the answer to any of these questions and your having serious sleep issues to the point you think you will die this is what you need to do. FOR YOUR SELF
questions you need to answer..
1. what happens when we sleep?
2. why do we need sleep?
3. what happens with out sleep?
4. what are the stages of sleep? e.g (R.E.M sleep)
5. what body processes cause us to want to sleep.
R.E.M sleep is the Rapid Eye Movement stage of sleep aka the dream state. where our body becomes extremely active even though your out like a light. this stage of sleep helps repair your body, This is the stage of sleep that most people with insomnia or other sleep disorders have trouble achieving, there are tests that can be done to see if your achieving rem sleep or not ask your doctor about it, its not a fun process as you will be sleeping in a bed with a few cameras on you and a little hat filled with wires and electrodes that measure your brains activity while you sleep. but it WILL answer alot of your questions and the doctor will know Exactly how to best help you.
once you know the answer to those very basic questions you can then work on fixing your problem, if your not willing to do some digging to find out the scientifically proven 100% fact, well then your problem isn't bothering you that much or its not that bad. (or your just really lazy and expect to be handed everything in life)
for those of you that do, you then can go to the doctor and you can state medical and scientific fact, not feelings which can be warped and can actually trick you into thinking you feel one thing when its something completely different.
(if your interested in testing what i just said, scroll right to the bottom and try my little experiment

)
ask your doctor questions like,
" well i know i need X, X, X to fall asleep, but I've done some research and i find that my body isn't doing that."
if your doctor is smart, that should trigger a question in there head
" something is missing or not working as its intended "
and will then work with you to figure out the cause of the sleep disorder, this way you will actually come out with a proper diagnosis and the correct medication to deal with that problem that has been taylord specifically for your own body chemistry.
avoid asking your doctor the following questions because there isn't anything they can do to help if you do ask these.
1. i can sleep give me something to sleep
likely response: umm..
2. i go to bed and just lay there for hours
likely response: "kinda figured that out on my own seeing as you said you can't sleep"
if all of this way to long and you didn't want to read.. here is the cliff notes.
1. learn what sleeping is and how our body actually achieves it.
2. learn the different stages of sleep and why there important
3. have a basic idea of what could be missing or wrong inside your body ( this way your doctor can help a lot faster and better )
if worst comes to worst, get your General practitioner ( your doctor ) to give you a referral to a neuro-psychological who specializes in sleep disorders specifically REM sleep which is the stage of sleep that actually does most of the repair work in our bodies. this will help you understand what is happening to you and will also help the " I'm gunna die" feeling you get from sleep deprivation. chances are you will solve your problem for a very long time if not fix it completely as most sleeping disorders now can be treated and cured.
now for that little experiment that i told you all about earlier.
Fill 3 glasses with water, 1 with ice, 1 just out of the tap and 1 with hot water ( not to hot that u burn your self)
now place your 1 hand in the icy water and 1 in the hot water, leave them there for about 20 seconds, and take notice of how hot/cold your hands feel.
now place both your hands into the glass with just normal tap water in it. you will instantly feel hot and cold at the same time even though the water is only 1 temperature.. your body has tricked you into thinking that the glass of water is both hot and cold at the same time.. when in reality.. its just normal temp
i am not a doctor, nor have a PHD in any medical fields so take this advice at your own risk and only do so if you feel that it will benefit you in the long run
wish you all sleep filled nights and dreams that never end.
Regards,
some one who also cant sleep (but is smarter then your average joe)