Meditation and mindfullness... which is more the act of non doing than doing. And yeah when your racing it seems impossible but if you just keep trying a few minutes at a time you will get the benefits even if you find it difficult. When I first started I would envision a flame or candle and just keep bring the mind back to it, or the point of a needle. Another is just laying down in a comfortable position and just bring your focus to your breath, but not manipulating the breath. Just feel the breath coming and going and focus on the feel of just breathing. Maybe try for 2 min and then try to increase the length of time.
Meditation is basically not turning the brain off but turning the thoughts off and just being. It's really helped me so much. When your mind wanders which it will just bring it back. It's so natural for our minds to constantly be doing but I swear its only because we were not taught how to be silent and still and just be completely present in the exact moment.
If you are worrying about things writing it out like suggested is great. Maybe after you write it out you can lay down or sit comfortably and just envision all the worries leaving out your finger tips..toes..head with every out breath and with every in breath envision all the clean vibrant white energy filling your lungs and passing through your viens further pushing out the worry on the exhales.
Worth a try anyways, I know I feel much lighter, clearer and calm even energized in a good way after some good internal clearing.
I hope you find some calm for that busy brain.

Genetic is always a wealth of knowledge and the lemon does help. As CheshireCatGrin said focus on the positive outcomes ( couldn't agree more ), give the positive some power by focusing on them and starve the negative possibilities off by lack of attention. I really think that does help us create the outcome we desire.
When you are reading it is sort of like meditation, the mind calms and stills, it become present on each word right in each moment. So yes maybe get some more books and make some time to sit and read if that was working and enjoyable.
I dont know if you read fiction and I myself don't read fiction often but this is kind of interesting
http://www.buzzle.com/articles/readi...editation.html explains much better than I did.