Dame Joan Collins fought back tears as she talked about the death of her sister Jackie Collins on This Morning.
The 83-year-old actress said she "cried for two or three months" after author Jackie died of breast cancer in September 2015, two weeks before her 78th birthday.
And she admitted that she sometimes has to pretend her sister is just in Los Angeles to make it easier.
Dame Joan told hosts Phillip Schofield and Holly Willoughby: "I miss her terribly ... I have talked about it.
"Grief is a process. I think I cried for two or three months, three to four times a day.
"And then you get over that and you kind of accept it in a grudging way and then you kind of think 'why did it happen' and then there's a certain time when you even become angry."
The former Dynasty star said it helps that she and her sister used to be apart a lot.
She said: "The only way I can get around it in a way is that I spend so much time in Europe and she would spend so much time in LA, so much of the time we weren't together - maybe together just four, five or six months of the year - so sometimes I think, 'She's in LA'."
Dame Joan was on the ITV programme to talk about her new one-woman show, Joan Collins Unscripted, which will tour the UK this autumn.
The star will be on stage with her husband Percy Gibson and will answer questions from the audience.
Dame Joan said: "He (Gibson) interrogates me. The audience will have 12 or 14 subjects that they can ask me about. Dynasty, Hollywood, filming ... as long as they don't ask 'Who was the best kisser?'"
Phillip and Holly joked: "That's a good question! So you know what our next question is?"
Laughing, Dame Joan replied: "It was Paul Newman of course!"