I've been giving this piece of advice to a lot of people lately, and it seems to be helpful:
Take a break from thinking. Even if it's only for thirty minutes, take some time for yourself to be free from your worry.
I guess I just see people stressing out a lot. It seems silly sometimes, because they get really bothered over things that don't really matter that much, but I think that people's minds will find equilibrium by blowing things out of proportion if they aren't serious enough. That's the only way people know how to live.
The problem comes when people do nothing but stress and worry over things. Sometimes, a person's mind just gets preoccupied with one thing over all others for a certain period of time. It happens to me pretty often, and it's almost impossible to just stop worrying about something. People might tell you that you need to "not worry about it", but when you deem it important, you can't get it out of your head.
That's why it's helpful to take a break from it. Allow yourself to go back to it later, but for a certain period of time, let yourself be free from your repetitive thoughts. Give yourself a break from worrying.
Sorry if the thought processes don't seem up to par this time, but Steve's playing DDR and he's really good, so it's almost impossible to concentrate. :)