Coronation Street star Kym Marsh is reliving the "terrifying" moment when she thought her teenage son was dying in front of her eyes.
In June last year, he had chest pains and was struggling to breathe, so she took him straight to hospital in Greater Manchester where doctors feared he was having a heart attack. She tried to hold back her own tears and be strong as 19-year-old David sobbed on her shoulder.
"I thought he was going to die, it was terrifying. He was terribly scared. A part of you can't believe this is happening to your boy, a fit young man," says the actress who's played barmaid Michelle Connor in the soap since 2006.
"As his mum, any crying or getting upset had to be done away from his room where he couldn't see it. All I could do was try to be positive and strong for him."
Her agony was heightened by the fact that she lost a baby son, Archie Jay, minutes after his birth in 2009, and had also seen her father suffer a heart attack when she was a teenager.
Although David has recovered - doctors diagnosed him with myopericarditis, an inflammation of the heart - he has been told his condition could return any time.
Marsh (38) is speaking out about the trauma because she wants to "give something back" by fronting the British Heart Foundation's Dechox campaign urging people to quit chocolate in March to raise money for heart research.
"I lost my baby son because he was born too early. I didn't want to lose another child," she says.
"He got headaches first of all, which he just thought was a cold and sinuses. But then when he started dropping asleep all the time and said his neck hurt I got worried because I thought it might be meningitis and took him to hospital," she says.
"The doctors also suspected meningitis and did a brain scan, which was clear. Although he had breathing difficulties and chest pain, he seemed better after an overnight stay and those symptoms were put down to indigestion."
But within hours of his return home, David - her son from her former relationship with Dave Cunliffe with whom she also has a daughter, Emilie (16), - was suffering such bad chest pain and breathing difficulties that Marsh rushed him back to hospital, and within two hours doctors diagnosed a heart problem.
"David didn't want to go back in because he doesn't like hospitals but I insisted. Thank God I did, it could have been such a different outcome - it doesn't bear thinking about. Sometimes it pays off being a neurotic mother!" she says with a smile.
"An ECG and blood tests showed he could be having a heart attack and he was put in the coronary care unit. He was so frightened and so was I because you have to take in everything the doctors are telling you.
"In the end, I broke down and asked a nurse what it all meant and she explained that they thought David had a virus which attacks the heart. She said, 'It's a very serious condition and it's vital it's treated quickly'. He underwent a battery of tests because they had to be totally sure what he had and the diagnosis was confirmed the next day. He stayed in hospital for 10 days."
His recovery has taken months and he has only just been allowed to return to work.
"For the first few weeks after he came out of hospital, he was out of breath every time he did anything and really just had to rest. His recovery was the same as if he had had a heart attack," she says.
"It reminded me of when my dad came out of hospital following his heart attack at 49. But I was looking at my son, a young man, being like that which was awful."
Her father (69) and also called David, has had a quadruple bypass and suffered a further mild heart attack two years ago. "Dad's been brilliant with David, supporting him, and helping him through it all.
"He knows what it's like to deal with the shock of something like this," she says.
"But it's been a real struggle for my David going through this. At one stage, he was quite depressed, and he's often said, 'Why has this happened to me?'
"Thankfully, after further medical checks to make sure he didn't have an underlying heart condition, he's just been given the all-clear and he's started to get his life back now, at work, driving again and going to the gym."
The knowledge that the virus could return is a stress that she's still coming to terms with.
"We have to be vigilant, of course, and if he occasionally gets a headache - one of the early symptoms - I do get a bit worried naturally," she says.
"It's still very fresh and raw at the moment but, as time goes on, we'll probably not be so paranoid about it."
Throughout the ordeal, Marsh, who also has a three-year-old daughter Polly from her marriage to ex-Hollyoaks star, Jamie Lomas (they divorced in 2014), has been supported by her fiance, personal trainer, Dan Hooper (31).
"I'm very fortunate to have met Dan, he's a genuinely lovely person," she says. "He's got a little girl as well, who's just a little older than Polly," says Marsh, who got engaged in December.