Most of the anxiety we suffer is from worrying about the future.  Most of the depression we suffer is from thinking about the past.  To bring down your stress levels, decrease anxiety and depression live in the moment.  Bring your thoughts back to what needs to be done today.  Think about what is happening right now this minute.  Be mindful of where you are and enjoy the little things you notice; the light coming through the window, a flower, the clouds, bird songs, smell of your coffee.  Stay with this.  When you wonder away to worry about what might not happen in the future, just come back again to this moment.   The more you practice this the better you will feel.