Advertisement was at home in Los Angeles, struggling to maintain his composure. “This past year has been the most difficult and painful year of my career,” he said. “It was excruciating.”The year has only gotten more intense for Mr. Musk, the chairman and chief executive of the electric-car maker Tesla, since he abruptly last week that he hoped to convert the publicly traded company into a private one. The episode kicked off a furor in the markets and within Tesla itself, and he acknowledged on Thursday that he was fraying.In an hourlong interview with The New York Times, he choked up...…Advertisement was at home in Los Angeles, struggling to maintain his composure. “This past year has been the most difficult and painful year of my career,” he said. “It was excruciating.”The year has only gotten more intense for Mr. Musk, the chairman and chief executive of the electric-car maker Tesla, since he abruptly last week that he hoped to convert the publicly traded company into a private one. The episode kicked off a furor in the markets and within Tesla itself, and he acknowledged on Thursday that he was fraying.In an hourlong interview with The New York Times, he choked up...WW…