Heidi Duckworth has had a cough for 10 weeks.
She contracted whooping cough - also known as pertussis - at the end of winter in late August.
"I've never been so sick in my life," said Ms Duckworth, of New Lambton.
She said whooping cough was "absolutely terrifying".
"I've never experienced that type of coughing. Impending suffocation is how I best describe it."
The illness, known as the 100-day cough, has become an epidemic.
About 2400 cases of whooping cough have occurred in Hunter New England this year, the highest on record.
The cases refer to those unwell enough to take a PCR test.
The Immunisation Foundation of Australia urged people to get up to date with whooping cough vaccinations.
Founder Catherine Hughes lost four-week-old son Riley from whooping cough complications in the 2015 epidemic.
"Whooping cough can be deadly for infants and lead to severe illness in older children and adults," Ms Hughes said.
She said people with asthma were "four times more likely to be infected and have a higher chance of being admitted to hospital".
Whooping cough is caused by the bacteria, Bordetella pertussis.
Ms Duckworth was treated with antibiotics, but had lingering symptoms similar to long COVID and chronic fatigue.
The illness left her with "exhaustion and soreness in the body and generally feeling unwell".
"I cough so much during the night, I can't get a good night's sleep," she said.
"A lack of sleep leads to other things like brain fog and general malaise.
"All the things I used to do sportwise and activity-wise, I just don't have the energy."
She hadn't been able to ride her horse Sofiana since she got sick.
"It's quite debilitating and ongoing. It's almost like two steps forward, one step back.
"I never imagined it would result in this length of time or ongoing symptoms. It's quite a shock."
The foundation's research showed one in four youngsters aged 13 missed out on their whooping cough booster last year.
Only one in five people aged over 50 was up to date for whooping cough vaccination.
NSW Health recommends adults get a booster at age 50 and 65, if they haven't had one in the last decade.
Adults working with young children, especially in healthcare and childcare, are recommended for a booster every decade.
Children are given the vaccine at age four, then a booster from age 11 to 13 through the school vaccination program.
The vaccine for pregnant women is free.
"I had a booster in the third trimester of pregnancy, but that was 18 years ago," Ms Duckworth said.
"It didn't enter my mind that I needed to protect myself from whooping cough with a booster."
Her doctors did not suggest a booster, despite having a health condition that made her more susceptible to infections.
She first experienced the illness after waking at 4am.
"I sat up in bed and was literally gasping. I couldn't get a breath," she said.
Her partner woke up.
"The look on his face was pure terror," she said.
"I didn't breathe for about a minute. When I started to breathe, it was that awful whooping sound."
She went to John Hunter Hospital for treatment.
"My partner and his children are unvaccinated," she said.
"He said if he'd known how serious whooping cough was, he would have immunised his kids."
