When I'm sad, and the usual distraction strategies don't work, I take myself off into my room, shut the door, close the curtains, and get into bed and lie perfectly still until I start to feel better. Concentrating on complete stillness and just letting my thoughts go wherever is like a meditation. It usually doesn't take too long for me to start getting some perspective on things and I suspect a huge part of the unresolved sadness is because of tiredness or being overwhelmed. Sometimes I am able to fall asleep, but that isn't the purpose of the exercise - just a bonus.
I've also found that if I start to lose the plot in the hot weather that floating in the pool with my eyes closed is almost as good. Either way it is the isolation that seems to do the trick.
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As soon as you trust yourself, you will know how to live. - Johann Wolfgang von Goethe