Kimberly Guilfoyle desperately tried to save her job after a Trump donor claimed she asked him to secretly pay off her $100,000 American Express bill ... going so far as to tell the White House the smoking-gun texts were fake and A.I.-generated.

The former U.S. ambassador to Greece resigned Tuesday amid a flurry of scandals ... but the Wall Street Journal reports she tried everything to stave off the inevitable.

Guilfoyle frantically called up top Trump administration officials and those closest to the President after the WSJ published text messages she sent to Trump donor Eric Deters.

Days before her July 2025 congressional hearing to become the U.S. Ambassador to Greece, Guilfoyle texted Deters ... "Honey please I need you to get this done for me today." She then sent him a PDF with instructions for paying an AmEx bill, telling Deters ... "You could just send it here."

Guilfoyle tried to claim the texts were fabricated using generative A.I. ... but the White House clearly wasn't buying it. Eric told us on "TMZ Live" the texts were legit.

There were other damning reports in the WSJ about Guilfoyle keeping a top lobbyist in her inner circle ... and accepting private jet travel and lavish hotel accommodations from a shipping magnate.

Trump told the media he didn't like what he was reading about Guilfoyle ... so he asked her to resign, and she stepped down ... but not before doing everything she could to save her hide.