(CNN) -- The notoriously private Janet Jackson opened up about her brother's death on "The Oprah Winfrey Show" Friday, admitting that the family knew he had a problem.
"People think we were in denial but we weren't. We tried intervention several times. He was very much in denial -- he didn't think he had a problem."
When the news first broke that Michael was ill, Jackson said she first heard about it from an assistant while she was home in New York. The last time she saw her brother was about a month before, she said, at a party she had thrown for their parents. "He was thin then, and we knew that he had a problem; we all did," she said.
His death, she told Winfrey, is "hard to believe still to this day. There isn't a day that goes by that I don't think about it -- that all of us in the family don't think about it -- every single day."
Her brother's passing happened right as Janet Jackson had started production on Tyler Perry's new film, "Why Did I Get Married Too?" and the emotional turmoil she was in comes through in the film, Winfrey said.
"It was very therapeutic," Jackson said of her role.
Tyler Perry, she added, was by her side the entire time, asking her how she wanted to be treated on set, making sure no one had access to images of Jackson crying in character (lest a tabloid run them as evidence of what Jackson was going through at the time), and even changing the ending of the movie, which opens nationwide Friday, for her.
"I changed the ending because at first she was going to speak at the funeral, and the things that she was going to say, it was too eerie," Perry, who also was on the show, told Winfrey. "She didn't want to change it, but I did."
Veering from the topic of his movie, Perry told Winfrey he felt the need to reiterate how hard the Jackson family worked to try to save their brother.
"I'm sorry, but I want people to know this," Perry said. "I want people to know how much they tried. They really, really tried -- the entire family. I want the whole world to know how much they tried."
The family was worried, Jackson said, and did several interventions. At one of them, Jackson said she became so overwhelmed, "seeing him and knowing that there was an issue that he was in denial about," she had to leave the room. "A lot of the relationships I've been in, they've had issues with addiction. It's difficult when you see it. [I] recognize it so quickly because I've dealt with it in past relationships."
For Jackson, it's difficult to even look at pictures of Michael as an adult or listen to his music; the only images she can stand to view are those of the pair as children.
"When we were kids, we had so much fun together," she said. "We used to spend every day, all day, together. I have a beautiful picture in my home of he and I when we were just babies. It takes me to that place, even when he was still here, that I missed, that we would talk about. That [picture] I can look at."
The emotional turmoil Jackson was dealing with, both in her role in Perry's movie as well as personally, began to affect her physically as well: Jackson said she's definitely an emotional eater.
"When I'm feeling down, I do turn to food," she told Winfrey. Her struggle with her weight has even led Jackson to write a book about it, to answer those persistent questions everyone always has about her weight.
"Instead of writing about nutrition, I decided to go into my childhood, where I've always had issues with my weight," Jackson said, adding that the book would touch on issues like self-confidence as well.