What he said is basically that he does think about quitting every day because it's a hard job that requires tons of sacrifices and has a huge impact on your personal life and all sane human would feel the same way and would constantly be questioning themselves if they were in his position.

He never said it the way English media is trying to depict it. He mentions in the same interview that he believes he still has something to bring to the table, especially with all the attacks on democracy and populism, he's not there to be popular, he's there to try and improve things.