Caitlyn Jenner Ready To Crack Over Dying Mother!

Caitlyn Jenner's beloved mom is facing her sad last days — and friends fear her death will plunge the sex-swapping reality star into an emotional tailspin.

"Caitlyn seems strong, but she's very fragile. Her mom, Esther, is the one person she can rely on," revealed a source. "I don't know what Cait will do without her."

In an exclusive interview, Esther Jenner told RadarOnline.com that she's battled several life-threatening health woes, including two broken hips, pneumonia and a dangerous lung inflammation called pleurisy, in the past 18 months.

"Now I've got an infection, so I started antibiotics again," Esther said from her rural Idaho home. "They're very strong. I hope they start to work, but so far there's no change."

Esther, who turns 90 in May, has lost all her siblings, but insisted she's not afraid of dying.

"I had two brothers and three sisters, and they're all gone," she told RadarOnline.com. "I'm going to take my turn. We all take our turn. None of us were born to live forever."

Caitlyn, 66, is completely heartbroken over her mother's decline, sources said, and even begged fans to pray for her mom, who she calls "my inspiration!"

"Please send good wishes and prayers to my mom," the former I Am Cait star recently posted in a message on social media.

Added another source: "Caitlyn is isolated from her kids at this point, and her mother is her emotional lifeline. Losing her would be devastating."

In a cruel twist, Esther's decline comes just as she bridged a decades-long divide with her child — who became world-famous after winning the 1976 Olympic decathlon gold medal as muscle-bound Bruce.

"Bruce was always keeping everybody at arm's length. Caitlyn is warmer and more ready to give you a hug. We talk on the phone almost every day," she recently revealed.

Gutsy Esther — who has outlived three husbands — said she battled back from a half-hip replacement to attend the ESPYs with Caitlyn in July 2015 when she accepted the Arthur Ashe Courage Award.

Shortly afterward, Esther suffered a devastating leg fracture.

"I don't fear death," Esther told RadarOnline.com. "My faith keeps me strong."

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