I find that emotional compartmentalization is a critical skill.
A couple years ago, I faced a very tough time in my life. My business was collapsing, my family's finances were in jeopardy, and there was a serious health issue going on.
The emotional stress was incapacitating. I couldn't sleep, let alone focus enough to fix my problems. It was the downward spiral nightmare scenario.
If I didn't have dependents (wife + 3 kids), I might have withdrawn into depression. Instead I was forced to fix my emotional state...
I constructed a personal prayer...
I am the man in the dark room.
In here, I am my loves, my principles, and my ideas.
Who I am cannot be changed by circumstances outside this room,
My loves are my legs which carry me to life outside this room.
My principles are my shield from the burdens the world assaults me with.
My ideas are the sword with which I shape my life.
When I return to myself in this room, the world remains outside, and I evolve to be better prepared tomorrow.
I found that even just stopping to say "I am the man in the dark room" was often enough remind myself that I wasn't defined by my circumstances.
To sleep, I found I could play the audio from old familiar TV shows to drown out the worries to fall (and stay) asleep - it was a surprising turn-around.
These two things changed my life. Hope this helps someone else.