“The Things You Can See Only When You Slow Down” by Haemin Sunim has been a best-selling book in South Korea since it appeared in 2012 (41 weeks atop the best-sellers list, 3 million copies sold in 3 years). It has now appeared in an English translation by Chi-Young Kim (Penguin, 2017).
Here’s some advice from the book, Chapter 2 – Mindfulness (When You Are Feeling Low):
If you wish to clear away the clouds of your thoughts,
simply keep your mind in the present.
The clouds of thought linger only in the
past or the future.
Bring your mind to the present,
and your thoughts will rest.
Rather than repeating,
“It is awful! It is awful!”
stare straight into the awful feeling.
Quietly.
Examine the feeling.
Can you see its impermanent nature?
Let the feeling leave when it says it wants to go.