The father, who died nearly a week before his son's first birthday, is calling for people to be vaccinated against the flu this winter.
Last winter, Adam Blackman didn't bother to catch and catch the flu.
The virus caused a life-threatening asthma attack. More than a month has passed in hospital recovery.
He said he "learned the hard way" about how dangerous the flu is and why people should be vaccinated.
Influenza viruses can mutate and change every year, so you need to be vaccinated annually to be protected.
Mr Blackman, 47, of East Sussex, said he grossly underestimated the risk of the flu.
While many people who catch it will recover within a week or so, the flu can be deadly to others, especially those at risk.
- Influenza that killed 50 million
- The teenager died after catching the flu virus
Asthma UK says colds and flu are the most common causes of asthma.
In Blackman's case, it resulted in pneumonia and lung collapse and meant that he had to be released into a coma for a week in hospital.
"I have asthma and my body just couldn't handle it," he says.
"I actually thought I was going to die before the ambulance got here.
"It was almost catastrophic for me, but my friends and family were also in danger.
"My asthma brother-in-law got sick right away and ended up in the hospital.
"I learned the hard way the flu could be life-threatening.
"I was addicted to a life machine and put it in isolation to prevent the flu from spreading.
"Given how infectious the flu can be, I would urge everyone to get the flu vaccine so they don't have to go through the hell I was going through.
"I don't risk it again and I already got the flu vaccine.
"I urge everyone with asthma to get it as soon as possible.
"It can save your life."
You can get the vaccine for free at the NHS if you:
- 65 or older
- someone with certain medical conditions, including asthma, heart disease or diabetes
- living in a long-term care facility or at home
- the main caregiver of the elderly or disabled
- a child aged two to 10 years
Many pharmacies and supermarkets have a flu vaccine service for clients.