Jackie Kennedy's "love for her children" saved her from deep grief and despair after President John F. Kennedy's death, a new book reveals.

Following her husband's assassination in 1963,  Jackie Kennedy would be haunted by recurrent nightmares and suicidal thoughts.

“In the spring of 1964, she actually thought about ending her life,” Paul Brandus, author of the new book 'Jackie: Her Transformation From First Lady to Jackie O,' told Closer Weekly. “She was miserable for quite a long time.”

Read More: Jackie believed Lyndon B. Johnson had John F. Kennedy killed

Jackie, who was 34 at the time, and her children, Caroline Kennedy and John F. Kennedy Jr., moved into a stately home in the Georgetown neighborhood of Washington, D.C.

“Can anyone understand how it is to have lived in the White House and then, suddenly, to be living alone as the president’s widow?” Jackie had said. 

The traumatized Jackie would often obsess over her late husband's assassination and what she could have done differently to save his life in Dallas

“She could not stop thinking about it. She had nightmares during the day,” said Brandus. “And going to sleep brought her no rest.”

She shut herself in her bedroom many nights, crying and self-medicating with alcohol.

“The term PTSD did not exist back then, but clearly she was traumatized,” said Brandus.

President John F Kennedy and his wife Jackie greeting the crowds from their motorcade on that fateful day in Dallas. Credit: GETTY

President John F Kennedy and his wife Jackie greeting the crowds from their motorcade on that fateful day in Dallas. Credit: GETTY

Jackie thought about ending it all. She asked Father McSorley, a priest Robert Kennedy introduced to her: “Do you think God would separate me from my husband if I killed myself?”  She told the priest she thought God was "unjust."

Although at times she thought Caroline and John would be better off living with Robert Kennedy and his wife Ethel, the children gave Jackie a reason to get out of bed every morning. 

“Her love for her children gave her strength,” said Brandus. “She said at one point that if you do a poor job of raising your children, then nothing else you do in life really matters. She lived up to that. They always came first.”

In the fall of 1964, Jackie left D.C. and moved with the children to New York. “She was always a New Yorker first,” said Brandus.

Jackie's younger sister Lee Radziwill was now only a few blocks away. Lee was the one who had introduced Jackie to  Aristotle Onassis several years earlier.

Although Jackie’s marriage to Onassis in 1968 would shock many, Brandus said it offered her the peace of mind she had been missing since Jack’s death.

Read More: John F Kennedy’s last words to his wife, Jackie, revealed

“Jackie didn’t believe the Secret Service could protect anybody — especially after the assassination of Bobby,” he said. “Whatever doubts she had about Onassis, they were outweighed by what he had to offer — first and foremost security.”

The Greek shipping magnate, who had enormous wealth, a private island, his own airline, and armed guards, made Jackie feel safe.

“He rescued me,” She once said. “At a moment when my life was engulfed in shadows.”