Hillary Clinton says she felt “emotionally drained” by talking to documentary filmmakers about her husband’s extramarital affair with White House intern Monica Lewinsky.

The 2016 presidential candidate told talk show host Ellen DeGeneres that the director of the four-part “Hillary” documentary — which premiered at the Sundance Film Festival and is set to debut on Hulu on March 6 — told her that “we’re gonna talk about everything.”

“I said OK, and yet when it actually came time, yeah, it’s hard,” she said.

Discussing the Lewinsky affair — which led to President Bill Clinton’s impeachment by the House of Representatives in 1998, before he was ultimately acquitted — was particularly difficult, she said.

“Staying in my marriage was the gutsiest personal decision I ever made,” she told DeGeneres. “So for me, revisiting that, talking about it, for my husband also to agree to be in the film and also to be asked, made it a bit difficult, there’s no doubt about it.

“But you couldn’t actually do a film about my life and not cover something that everybody knew about,” she added, “because you could read about it, and everybody had an opinion about [it].”

Clinton added that her decision not to divorce her husband drew some harsh criticisms.

“It’s fascinating because as you go through the film, some of the women who have been my friends and who have supported me personally and every other way, they talked about how so many women would be really upset because I chose to stay with my husband,” she said. “And they would go and talk to these women. And a lot of the women would say, ‘I can’t support her, I don’t like her because she stayed with her husband.’

“But then they would say, ‘OK, why is that?’ ” she continued. “And people would talk and pretty soon they would say that happened to my sister, that happened to my friend, and I always said everybody needs to make the best decision for you and your family.”

She said that she often faced a double standard.

“It was such a strange conversation because some of the very same people who would say, ‘I could never support her,’ would say literally in the next breath, ‘But I love her husband, I love Bill Clinton,’ ” she said.

“Well I do too,” Clinton quipped. “But it was a really emotionally draining experience to go through it again. But I have to say, once I saw the whole four hours of the documentary, I hope that our talking about this, my willingness to address all of this, really does help other people.”