Vicky Phelan has been forced to pull out of Charlie Bird's Croagh Patrick climb as her health deteriorates.
The cervical cancer campaigner had to make the "hard decision" as she gave followers an unfortunate health update.
Sharing a photo from her bed in Milford Care Centre in County Limerick, where she was recovering from complications which occurred during radiotherapy treatment, she revealed that "nothing could have prepared me" for her recent experience.
She said: "I am going home after spending the past two weeks in this room.
"I have NEVER been so sick or in as much pain as I have been over the past two weeks!
"The radiotherapy increased the amount of pain I was in and also incapacitated me leaving me unable to walk without assistance. I am only now, in the past few days able to walk without either a 4-wheeler or a Zimmer frame. Walking long distances is still beyond me but I hope I will get there again."
Continuing to detail her current health situation, she then gave the unfortunate update that she has had to pull out of the Croagh Patrick climb with Charlie Bird which she was supposed to take part in this April.
She wrote: "I am simply not well enough either physically or mentally. The past few weeks have really knocked the stuffing out of me and I need to focus on just getting well again.
"I have already been in touch with Charlie and he has been great about it."
She added: "I am also going to pull back from posting here on social media. I need to focus on spending time with my family and friends. I hope that people understand."
Vicky and Charlie connected after Charlie's emotional appearance on The Late Late Show last year when he gave viewers an insight into his life with Motor Neuron Disease.
Charlie will take on Croagh Patrick on April 2 while people around the country will host their own walks, all with the aim of raising funds for Irish Motor Neurone Disease Association and Pieta House.
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