When Desi Arnaz was deep in the throes of alcoholism, he turned to his son, who faced his own struggles with addiction, for advice."Desis second wife had died," author Todd S. Purdum told Fox News Digital. "He was alone. He knew he was drinking too much. He knew he was drinking himself to death. And he turned to Desi Jr., who was sober by then, and asked for help.""His son said, I cant help you, but I know a place that can,'" said Purdum. "Desi was smart enough to know that he was throwing his life away. He was in terrible grief and mourning He was isolating himself. I think he realized that he had to change something, or he was going to die."CLINT EASTWOOD'S COMPLICATED LOVE LIFE, 'ADDICTIVE' AFFAIRS EXPOSED IN NEW BIOGRAPHYThe entertainer, who famously starred as Ricky Ricardo opposite his first wife Lucille Ball in the 50s sitcom, "I Love Lucy," died in 1986 at age 69 from lung cancer.Hes now the subject of a new biography by Purdum, "Desi Arnaz: The Man Who Invented Television." It explores the late actors rise to stardom and how he revolutionized television production, as well as his final years. For the book, Arnaz Jr., 72, gave a rare interview."His sister from the very beginning, Lucie Arnaz, had been an invaluable help to me," said Purdum. "She cooperated from the beginning, giving me access to family letters and documents. I had a series of long talks with Desi Jr. before we had an on-the-record interview. And I think he understood that I was trying to tell his fathers whole story. He knew I would be sympathetic but wouldnt spare the complications of his life and demons.""I think he saw that I was trying to understand his father, what made him tick, what made him so talented, but also the forces that undermined him in the later part of his life where he was swallowed up by alcoholism and depression," Purdum shared.According to Purdum, Desi Jr. sought treatment in 1981. His father entered an alcohol rehabilitation program in 1985 under the name "Bill Sanchez" to protect his privacy. Before seeking help, Lucie recalled how their father called Desi Jr. and pleaded, "I need help. I dont want to die."At first, Arnaz resisted treatment. After a few days, he even left the hospital.CLICK HERE TO SIGN UP FOR THE ENTERTAINMENT NEWSLETTER"Desi was proud," said Purdum. "He believed you shouldnt air your dirty linen in public or talk about it with other people. He was stubborn in that way. And alcoholism was much more stigmatized back then."Still, Arnaz returned to the program and persisted."We were there for him, the proudest moment of my life when he stood up and said, My name is Desi, and Im an alcoholic," said Lucie, 73, as quoted in the book. "I cried my eyes out. I was so proud of him."Purdum described how Arnaz turned to the bottle long before his Hollywood success to drown out a painful past."I think Desi suffered from what we would now call PTSD," Purdum explained. "He had to leave everything behind in Cuba when he was a teenager. His family lost everything to the revolution. They came to this country without a penny in their pockets."I think the aftermath of that disruption took a toll on him for the rest of his life And certainly, there was the stress of running a big and growing business as a mogul. I think he sought some self-anesthetization, some relief, and alcohol was the safety valve that he turned to."WATCH: I LOVE LUCY STAR KEITH THIBODEAUX RECALLS PLAYING LITTLE RICKY, WORKING ALONGSIDE LUCILLE BALL, DESI ARNAZ"He writes in his memoir that hed always enjoyed drinking," Purdum continued. "Hed always had a big appetite for drinking He loved food, drink, women and song. And he seems to have been the kind of person who grabbed life by the handful."Arnaz and Ball said "I do" in 1940. Their marriage was plagued with problems, mainly due to their separate careers, along with Arnaz's womanizing and drinking. "I Love Lucy," which premiered in 1951, was designed to save their marriage, The Associated Press reported."One of the things that went wrong was they started the show so they could be together," said Purdum. "They could live together in Los Angeles and work together. Desi was on the road with his band a lot. Lucille was making movies in Hollywood. They were often separated. So the show was created partly to save their marriage."But theres a strain from being together 24/7, not only at home, but at work too. That puts a lot of pressure on any relationship And Desi, as he got more successful, fell more and more prey to drinking.""He was out of control, both with his alcohol consumption and his womanizing," said Purdum. "I think it just became too much for Lucille to take. But they always stayed connected. They never stopped loving each other. Im sure of that But I think all the pressures they faced would be a big burden on anybody. And I think that burden was reflected in their lives."According to the book, some of the couples friends claimed that the final straw for Ball came when she found Arnaz "with two hookers" in their guesthouse. Ball told some confidantes that it was she who sought the divorce.LIKE WHAT YOURE READING? CLICK HERE FOR MORE ENTERTAINMENT NEWS"She always knew or suspected that he had been unfaithful to her but it was private," said Purdum. "Lucille didnt like it, but I think she could sort of tolerate it [But] then it became very public. It was written about in the tabloids when Desi got arrested for weaving drunkenly down a street in Hollywood, in a neighborhood of brothels. I think it just became overwhelming for her and too much to take in public.""I think she was also worried about the toll that their fighting was taking on the children. She said at one point that the children had seen and heard too much of the tension between their parents. She decided that it would be better for the children to come from a broken home than to live in one."Arnaz and Balls children told Purdum that they knew their parents loved them and did the best they could."They are both aware of how their parents fell short," said Purdum. "They also understand that it must have been very complicated to live in that reality."Arnaz and Ball called it quits in 1960. Both went on to remarry, with Ball tying the knot with Gary Morton in 1961 and Arnaz to Edith Mack Hirsch in 1963."He had a happy marriage to Edie, a friend that hed known," said Purdum. "He was not faithful to her either, because thats just the way he seems to have been wired. But I think Lucille was the great love of his life, and he was the great love of her life. They never felt about their second spouses the same way they felt about each other."After Arnaz sought alcohol treatment, he never drank again. But just a year after seeking help, he faced a major blow when he was diagnosed with lung cancer.When he was dying, he and Ball had "long talks" as they reminisced about the past. Their last words to each other were "I love you," on Nov. 30, 1986, which would have been their 46th wedding anniversary.Two days later, Arnaz passed away."He got better too late," said Purdum. "I think thats one of the things thats very sad about the last part of his story. He did finally have the courage to face some of his problems, but not in time to save his life.""To his children, Desi was a complicated, but very loving, talented, self-taught visionary," said Purdum. "Ricky Ricardo is a wonderful character, and Desi did a good job of playing him, but hes not just some guy who talked funny and played the drums. He was a remarkable figure, and I think thats really worth knowing."