 -- Jennie Willoughby, the ex-wife of former White House staff secretary Rob Porter, lashed back at President Donald Trump Sunday, saying Trump has implied she's "a liar" after going public about the alleged domestic abuse she says she endured with Porter during their marriage.

In an opinion piece posted on Time.com, Willoughby writes, "President Trump will not diminish my truth."

"The truth exists whether the President accepts it or not," she wrote.

Willoughby responded to comments Trump made in the Oval Office Friday and to his tweet Saturday morning expressing concern about lives being "destroyed" because of “a mere allegation.”

“Some are true and some are false,” the president tweeted. “There is no recovery for someone falsely accused - life and career are gone.”

Willoughby wrote, "There it is again. The words “mere allegation” and “falsely accused” meant to imply that I am a liar. That Colbie Holderness is a liar," she wrote referring to Porter's first wife who told ABC News Porter abused her as well. "That the work Rob was doing in the White House was of higher value than our mental, emotional or physical wellbeing. That his professional contributions are worth more than the truth. That abuse is something to be questioned and doubted."

In the Time piece, Willoughby said she wasn’t surprised the president praised her ex-husband’s work to reporters Friday. "But when Donald Trump repeated twice that Rob declared his innocence, I was floored,” she wrote.

Willoughby questioned why the president thought Porter’s professional contributions in the White House outweighed what he did behind closed doors.

"Everyone wants to talk about how the White House and former colleagues defended Rob. Of course they did! They valued and respected him. The truth would be dissonant to everything they believed to be true about the man they knew. The truth would be devastating. And denial is easier than devastation, " Willoughby wrote.

Willoughby has confirmed to ABC News she notified the FBI about Porter’s alleged abuse while they were conducting a background check on him. Porter has denied the allegations.

But Willoughby thinks the domestic violence issue is much deeper than what Trump and her other ex-husband’s colleagues think.

“Society as a whole doesn’t acknowledge the reality of abuse," she wrote. "Rather than embarrass an abuser, society is subconsciously trained to question a victim of abuse,” Willoughby continued.

Willoughby went on to encourage other victims of domestic violence to no longer be afraid to share their stories.

“And for any men, women, or children currently in situations of abuse, please know: it is real, you are not crazy, you are not alone, I believe you.”