KATIE COURIC fought off the painful memory of her husband’s death from cancer 3 1/2 years ago to bravely support her sister Emily as she succumbed to the same killer disease.

But after 54-year-old Emily Couric’s death from pancreatic cancer on October 18, the “Today Show” host collapsed in tears and had to be virtually carried out of a Virginia funeral home by her nephew, an insider told The ENQUIRER.

“Katie sobbed, ‘I’m going to miss her. We all wish we could have done more. But Mother knew how much we all loved her.’ “

Katie, 44, was at her older sister’s side when she died at her home in Charlottesville, Va., as was Emily’s entire family — her husband of 20 years, Dr. George Beller, her parents John and Elinor, brother John Jr., sister Clara Couric Batchelor, two sons and three stepchildren.

“Emily died the way she wanted — with all her loved ones around her,” a source declared.

“And Katie was a rock the last few days and hours.”

For three nights, Katie slept on a cot beside her stricken sister, ministering to her needs in her last hours, said a family friend.

“Katie held Emily’s hand, wiped the sweat from her brow and told her how much she loved her.

“Katie was there when they gave Emily morphine for the pain and when they fed her intravenously. She helped drive away the fear she sometimes saw in her sister’s eyes, whispering words of love and encouragement — even though her heart was breaking.”

In the last days as Katie sat at her bedside, Emily reversed roles and offered Katie encouragement, said the family friend.

She urged Katie — whose husband Jay Monahan died of colon cancer at age 42 in January 1998 — to wed TV executive Tom Werner, Katie’s boyfriend for more than a year.

Werner filed for divorce from his wife of 28 years last October. “Despite her pain, Emily’s thoughts were for Katie’s future,” the friend revealed.

“She told Katie that she needed to go on with her life, and if she truly loved the man in her life, she should marry him.

“Tom was one of the first people to call Katie to offer sympathy after Emily’s death. When she heard his voice, Katie broke down.

“She told him, ‘My heart’s been broken for a second time. But I’ve got to be strong for the sake of my parents, for my own daughters.’ “

Emily, a Virginia state senator since 1996, was so popular and highly respected in Virginia that it was widely believed she would one day become the state’s first woman governor.

On October 22, Katie celebrated her sister in a moving eulogy at a public service at St. Paul’s Memorial Church in Charlottesville, attended by 2,000 people — including her co-host Matt Lauer.

Katie fought back tears several times during her tribute. Twice she had to stop and drink from a glass of water to compose herself. And she made an emotional reference to her beloved Jay’s passing.

“When my husband died,” said Katie, her voice cracking, “Emily decided to act,” and Virginia became the first state in the nation to pay for color cancer screening tests.

“I can’t think of a better tribute to Jay and now a lasting tribute to her. She taught me not about dying, but about living.”