How do you fall asleep with the weight of the world on your shoulders?!

How do you fall asleep with the weight of the world on your shoulders?

Its 3am and I can't sleep. It seems if it can go wrong it has gone wrong and my mind just wont let me sleep. Ive tried counting sheep and tried to think good thought and well just about everything else. I know it could be worse don't get me wrong but, how do I turn my mind off....

I had this problem on and off most of my life.
Alcohol does help sometimes.
The real problem is not sleep but your mind.
When I looked at all the issues at once it was overwhelming and I became anxious and excited and thus could not sleep. Then I would think, now I will be all sleepy tomorrow and not be able to do anything and I would get more anxious.
I ended up reading a lot of philosophy. What I gleaned from it was that I had to prioritize and evaluate the importance of obstacles and problems. Is this problem going to ruin everything? Probably not. Let it go. Do I have any control over this issue? No? Why am I worrying about it? Let it go. Whatever is left, write it down in a list. Prioritize the items and list possible solutions under them, even stupid ones, just to get them down and out of your head. For big questions, life changing ones, like college, job changes, career choices, and the like. Try writing down pros and cons, write down emotional pros and cons too. For issues involving others, remember that you come first. You are the only one who will look out for you 100% of the time. Others can give advice but you are the one that lives with your choices. You have the right to make choices that make you happy, and sometimes those choices will make others unhappy. You are not responsible for their emotions.
Hope that helps.
The Tao of Pooh is a good book to read.
Also The way of the Peaceful Warrior (although a bit cheesy) but it is directly related to your problem. The character in it has a mind like a racing locomotive.