The editor of a left-leaning British newspaper offered its staffers counseling to cope with Donald Trump’s “upsetting” victory in Tuesday’s presidential election, The Post has learned.Katherine Viner, editor-in-chief of The Guardian, urged journalists at the newspaper’s UK and Australia offices to contact their colleagues in the United States to “offer your support,” according to a copy of her email obtained by The Post.“I know the result has been very upsetting for many colleagues,” she wrote..“If you want to talk about it, your manager and members of the leadership team are all available, as is the People team.”Viner added that employees upset by Trump’s return to the White House can access free mental health support from internal company portals, according to the memo.“The election has exposed alarming fault lines on many fronts, which we will be examining in the weeks and months ahead,” Viner wrote.One source trashed the Israel-bashing newspaper’s offer of counseling as “dumb s—.” Another mocked any triggered journalist, saying sarcastically: “It’s all so difficult!”The Post has sought comment from The Guardian.The newspaper’s front page on Thursday showed an image of a smiling Trump with the headline: “American dread.”Viner — who has been in charge of 203-year-old London publication since 2015 — also attempted to fund-raise off of Trump’s political comeback, which she called “an extraordinary, devastating moment in the history” of the US.She penned an essay Wednesday urging readers to donate in order to help it “stand up to four more years of (Trump).”“We will stand up to these threats, but it will take brave, well-funded independent journalism… that can’t be leaned upon by a billionaire owner terrified of retribution from a bully in the White House,” Viner wrote, alluding to Washington Post owner Jeff Bezos.Bezos, the Amazon founder, blocked his editorial board from endorsing Harris, sparki...