Lynda Bellingham is hoping to make it to Christmas to celebrate her favourite part of the year for one last time, surrounded by her family.

The 66-year-old actress and presenter has just revealed that she has terminal bowel cancer, and plans to stop chemotherapy in November, so that she can have some quality of life in the time she has left.

Meeting her today, the former Loose Women panellist and Oxo mum looks a shadow of her former self. The weight has dropped off, and the hair is now wispy and white, not the full head of lustrous brown locks she once had. She has painful ulcers in her mouth and throat, and has lost her sense of taste.

She has also become breathless - although she hides it well, shows me her blackened fingers which give her constant pins and needles, a side-effect of the chemo, and tells me that in the past week her legs have weakened, which she thinks is because she recently decided to halve the chemo drugs.

"I want Christmas Day more than anything else - it means everything to me. I missed it last year. If I can do Christmas, that will be great. Knowing that I've made the decision to die and I am in control of it... I accept it. There's nothing to be frightened of.

"We may do Christmas lunch out, but I want presents and pudding in my house around the tree."

Then she adds: "My oncologist said, 'My fear is that I won't keep you alive until Christmas'."

Her third husband, property developer Michael Pattemore, who has been her constant companion and carer throughout the ordeal, is with her, checking she has everything she needs, barely able to contain his emotions when asked how he is going to cope when she is no longer here.

"Michael has been amazing. We finally found each other late in life, and the saddest thing for me is that we'd planned to work hard for the next five years, and then travel and enjoy the rest of our lives together. He's finding it very hard to hide the stress from me," she says, at which point Michael begins to cry.

She may not be able to control her own life, but she has organised everything for when she is gone - her will, her funeral wishes and even her grave. Michael has booked two plots for him and her in the Somerset cemetery where his father is buried.

Lynda's body may be weak but her mind is still willing, and she has now written what is likely to be her final memoir, There's Something I've Been Dying To Tell You, charting her painful journey since she was diagnosed in July last year and, in her own words, entered a world of cancer.

The bowel cancer was already stage four when it was found, with lesions on her lungs and liver - so why would she want to devote the last year to writing about the whole tragic story?

"The book gave me a discipline, helped me to keep a focus on life," she says now.

While the details of her illness are heart-wrenching, Lynda's memoir is peppered with humour, from naming her cancer FU2, to a hilarious episode where she ended up kneeling in the loos at Buckingham Palace - where she received an OBE for her charity work - in an effort to empty her stoma bag, which she nicknamed Furby.

"Bowel cancer isn't sexy. So I thought I would get it out there and make it funny," she reflects. "Bowel cancer is the third biggest killer. It kills more people than breast cancer and unfortunately, a lot of the time, once you're diagnosed with it, it's too late."

She had suffered from bouts of terrible indigestion and diarrhoea, but despite tests, remained undiagnosed for some time. When the tumour was found, she was immediately referred to the London Oncology Clinic.

"When we got to the clinic, you walk through those doors and you're in that world of cancer. There were people with headscarves, people who were weak or defiant. I suddenly thought, 'Oh my God, I'm really ill'.

"When I was diagnosed, it was such a shock, the first thing you do is think negatively, you think death. But I want this book to be about somebody giving you a new life, a bit like the Invictus Games.

"Once you've got over the shock, you must then say, 'Oh, right, I'm not going to do this life then, I'm going to do another life', and grasp it, because it gives you something to focus on and creates an energy."

The oncologist believes Lynda, who has worked for several cancer charities over the years, had cancer for around 18 months before it was finally diagnosed, and initially predicted she would survive between two to five years.

However, last December she was rushed to hospital in agony, as the tumour had perforated her bowel, requiring emergency surgery. This major setback reduced her predicted survival time, she recalls.

"I accepted that I was going to die, but at that point, time is bizarre. I accepted there was a horizon and I accepted that I was going to have to work at this. I didn't fool myself into thinking there was going to be a miracle cure.

"People come up with all these amazing cures and diets, but sorry, once you're stage four, cancer is personal. Everybody is different. I've tried to show people where it took me."

Lynda, who has two grown-up sons, Michael and Robbie, and stepson Bradley, says: "I have tried very hard not to cry in front of the boys, and I am also aware that Michael is trying to stay positive as well, but every now and then, things just well up, and it is important to acknowledge these down moments."

She's not scared of dying, but more concerned with how she'll say goodbye. She wants to die at home and has made provision for Macmillan nurses to be there.

"I'm quite nervous about saying goodbye but I don't fear death. I'm not religious but I am a Christian, and I like to think there's somewhere else to go."

She would like Michael to find a companion after she's gone, she says.

"He'll never marry again, but I would love him to find somebody that he could remotely share his life with. I know he says he won't, but I think it's lovely to have somebody to share things with."

She's finished her second novel, The Boy I Love, about a band of actors in the early Eighties, which is to be published in January, but doesn't know if she'll be around to see it in the bookshops.

In the meantime, she's hoping to go on one final holiday with the family. "Suddenly, memories are really important."

She hopes her legacy will be to pass her energy on to her sons, to enable them to get the most out of their lives and move forward.

"If you feel like giving up or lying down under the duvet, don't you dare, because I will be round every corner haunting you, with the inimitable words that crop up all the time in our household these days: 'Stop yer whingeing, at least you haven't got cancer!'"

:: There's Something I've Been Dying To Tell You by Lynda Bellingham is published by Coronet on October 9, priced £20