As we have seen, our brain is hard-wired to worry. So how can we stop worrying? Unfortunately you can't, but what you can do is control the amount of worry that you do. Trust me when I say that you can control it, I am the biggest worrier in the world.
Worry starts first thing in the morning as soon as we wake up. Our brain goes straight to worrying so that we are ready for the day's dangers that lie ahead. If you do this, and I used to do it every day, force your brain to think about one positive happy thing that is coming up later in the day. If you can't think of one, then look further ahead to something positive happy thing coming up later in the week.
Throughout the day if you find yourself starting to worry then look closely at what it is that you are worrying about. Put the topic into perspective by writing it down and then look at the facts. Say to yourself, "What is the very worst thing that could happen" then list everything that could go wrong. Beside each thing that could go wrong write down the likelihood of it happening and what you can do to stop it from doing so.
The military use a version of this when they are planning a coordinated action (battle). They say to themselves, “So what, therefore”. So what could happen and what can I do to counter it. By doing this you will find that your brain will begin to stop worrying because you have provided it with an answer for each situation. Your brain worries about the unknown, that’s how it keeps you safe.
There is a similar method that you can use if you don't like the military version. I developed a mathematical equation to make it easy to remember (I know, I am a nerd) P-A=R. Our Perception minus our Attitude equals the Reality. It is our perception of something that exaggerates our worry. Our perception is based on previous learnings, what we have learned over our lifetime. Our learnings form our attitude. Unfortunately this is the wrong way of looking at a problem. By changing our attitude into a positive one you then change your perception which brings you back to reality.
In the evening, if you are still worrying about things then again write them down and work through the pattern of 'so what, therefore' or use the PAR technique. Once you have worked through the worries you will be more relaxed and so will your brain be. Plus, by writing it down you have lodged the worry into your subconscious which will continue to work out an answer to your problem.