Your brain on gratitude
The Science of Gratitude
"Research shows that adopting an attitude of gratitude, simply expressing appreciation and being more thankful, can measurably improve your overall well-being."
The Amazing Effects of Gratitude
"A(...) study asked people to write down three things that went well that day and why for one week. At the end of the week, people were slightly happier than at the beginning, and over time, their happiness scores kept improving. After one month, they were 5% happier, and after six months, they were 9% happier. Just from one week of writing a journal."
You aren't at the mercy of your emotions - your brain creates them
"But I am telling you that you have more control over your emotions than you might imagine, and that you have the capacity to turn down the dial on emotional suffering and its consequences for your life by learning how to construct your experiences differently."
And here are some great articles
(there's a lot more, I had to make a choice)