JAMES GARNER has fallen into a deep despair after the death of his close friend and “Maverick” co-star Efrem Zimbalist Jr., say friends.

The once-imposing actor, who’s now 86, spends most of his days confined to his bed in his Southern California home.

“Jim’s convinced that he’s next to go,” said a source. “He was devastated by the death of his friend Paul Newman. Now, Efrem’s passing has gut-punched him again.”

Newman died of cancer in 2008, while Zimbalist passed away on May 2 at the age of 95.

Garner was too distraught to make a statement after Zimbalist’s death, but his official Facebook fan page acknowledged the loss and posted a photo of the longtime friends together at Zimbalist’s 90th birthday party in 2008.

Garner found huge success on both the big and little screens. Along with movies such as “The Great Escape” and “Victor Victoria,” he starred in “The Rockford Files” on TV more than a decade after “Maverick” wrapped in 1962.

Sadly, he’s been battling health issues for years. In 2008, he was photographed in a wheelchair and using a cane to walk after he suffered a debilitating stroke. In 2013, The ENQUIRER reported that he suffered a second stroke not long before his 85th birthday.

He has wrestled with blue moods in the past.

But Efrem’s death has really laid him low. And, according to the source, Garner was looking forward to making a cameo in a theatrical version of “The Rockford Files,” starring Vince Vaughn, which is currently in pre-production. But he’s too ill to take part in the show.

“That was the last straw,” the source added. “Jim feels like he can’t go on.

“He’s got nothing left to live for.”