“What’s your name? asked the woman sitting opposite me. I stared at her in complete disbelief. Stunned into silence, I could feel a ripple of anger starting to build inside me. Pain spread across my chest, hurt ripped through my heart, as I fought back the burning tears in my eyes. I wanted to shout, ‘how dare you ask me what my name is’. Instead, I blinked back my tears, forced a smile, and said, ‘my name is Cassie’. Her eyes softened, a gentle smile appeared on her face, and with all my might I prayed that she would remember.”

These powerful words form part of the introduction of a new book written by Cassandra (Cassie) Farren who wants to share the heart-breaking story of her mum's descent into dementia.

Cassie talks candidly about her own painful journey, from the early days when her mum became more and more forgetful to the soul-destroying moment she no longer recognised her daughter.

She describes how she, her dad and her sister struggled to come to terms with their own painful loss.

Cassie, aged 39, who grew up in St Neots and attended Longsands School, launches her book, I've Lost My Mum this week, which marks Dementia Action Week.

It charts her early suspicions that her mum's forgetfulness could be something more serious and describes how she and her dad struggled to obtain a diagnosis. It also covers the heart wrenching moment four years later when they made the decision to start contacting care homes.

In the early days, Cassie says her mum began to repeat herself and would often tell the same story several times each day. It was always an old story, usually something from her childhood.

The formal diagnosis came via a letter from the GP and Cassie admits she and her dad felt isolated and unsure about what the future would bring.

She said: "Dementia is an invisible illness. When mum walked down the street or we went out to lunch, no-one knew she was ill and gradually she withdrew and stopped taking part in conversations. It builds and builds until there is a cut-off point in the brain - almost like a computer being full - and the brain can't accept any new information."

Cassie says once her mum began to wander off and her dad no longer felt he could keep his wife safe, they decided full time care was the best option. She describes this harrowing experience in the book.

"My mum had begged me never to put her in care and I looked her straight in the eye and promised her I would never do it," says Cassie.

"It was the biggest lie of my life to the woman I loved the most."

In February 2018, she writes: "That conversation I'd had with my mum just one week before was stuck in my head like a broken merry-go-round.

"I couldn't turn down the sound of the terror in my mum's voice. I couldn't get rid of the look of panic I had seen in her eyes; I couldn't erase the feeling of her gripping my hands tightly as she begged me to make a promise I knew I couldn't keep."

Cassie believes there are hundreds of families out there who are at breaking point because they don't know where to get help and she hopes her book will provide emotional support as well as useful information.

At the present time Cassie's mum continues to decline and is receiving full time care in a care home.

She often recognises her husband, but not Cassie.

Cassie has made the decision not to name her mum in the book to protect her dignity and privacy.

Cassie admits she had to bear her soul to write the book and although she was determined to make a difference, there were days when she was too emotionally overwrought to write, and she seriously questioned whether she would have the emotional strength to finish it.

"I started out with the intention of writing between 500 and 1,000 words each day, but some days I just had to stop as I couldn't see the computer screen through my tears," she explained.

INFO: Dementia Action Week is organised by the Alzheimer's Society, which says every three minutes someone in the UK develops dementia. It encourages individuals, workplaces and communities to take action and improve the lives of people living with dementia.

Contact: www.alzheimers.org.uk or call the dementia helpline on: 0300 222 11 22. Dementia UK on:0800 888 6678 or www.dementiaaction.org.uk; www.dementiafriends.org.uk.

I've Lost My Mum is available on Amazon.