I have no problems sleeping, which is quite amazing, since as a child I use to have issues. These days I hit the pillow and I'm out within a few minutes.
I do remember I use to have a similar problem, staying up thinking about stuff that stresses me out. And then, one day, I had this grand realization that I thought about stuff at completely the wrong time.
If your going to worry about stuff, school yourself to worry about it when you can actually affect it. This is the most important thing you can do when it comes to managing stress and fears.
At 1am in the morning, there is nothing you can do about a bill that needs to be payed, or a conversation that needs to be held. Your literally wasting mental capacity by worrying when you can't do anything about it right then.
And catch yourself when you start to steamroll your own mind. People love to think about one thing, realize it's a problem, and then move onto another problem, and try to realize how grand it is. Instead of sticking with the first problem and reasoning it out. So by hopping from one bad thing the next, your basically just panicing yourself.