Stop watching the news. Change the button on the radio when the song is done. Turn your head as you pass the stack of papers full of doom. Just stop.
I know it's not realistic, responsible, or right. But I'd sure like to have oh, let's say three days without hearing about anyone who's homeless, starving, injured, going bankrupt, or suicidal.
Maybe that's why historicals appeal to me. The events I write and read about are over; the people long removed from whatever pain and suffering they endured. I'm in no way responsible: I don't have to speak out against the Spanish Inquisition, send money to help victims of the Bubonic Plague, or worry about the future of those who lost everything on Black Tuesday. I don't even have to decide whether to vote for Lincoln or Douglas.
Today's technology means that we know every disaster intimately. If you don't have enough trouble in your own life, you can share in the anguish of others. It's wonderful that we know, that we can write letters or send money or even travel to places where our help is needed. But it also can be crushing. There's no end to the suffering of man (and we even stress over the suffering of beasts and plants these days). I recommend that you do what you can, but also that you take a break from it when it gets to be too much.
In fact, I recommend that you read a good novel, one where nothing you do can change a thing.