You ever think about blogging? Open up a blog on Blogger.com and just blog your thoughts and plans. You can set it to private so nobody can see it if you don't want. It's a good way to spill out all your thoughts, sometimes it can help.
Also you might want to try to lay down with the lights off and listen to music, that can help get you to sleep as well.
Also, have you ever tried audio books? There's free audio books all over the net (even on YouTube), that you can lay down and listen to at night and it can put you to sleep while you listen.
Those are all solid ideas, but I find that the best cure for insomnia is to drink heavily until you are no longer awake.