'"I had just been out for a 10km run, got home and then had a massive grand mal seizure in front of my flatmate."
She woke up in hospital thinking she was just dehydrated, but then a doctor revealed that in fact she had cancer - leaving her "in shock". The seizure was her first and only symptom.
The cancer has returned three times despite treatment, Tarrant explained.
"Brain cancer grows so slowly that your brain can mask it by transferring the processes to another section. So by the time it is found it is often too late ... that's the scariest thing, it is a silent killer."
She had brain surgery in November 2010, as doctors attempted to remove as much of the tumour as possible without trimming away healthy brain tissue.
But just days after the operation, Tarrant suffered a major edema - swelling caused by excess fluid trapped in her body's tissues. It left her dizzy, nauseous and thinking she was going to die, she recalled.
"I was vomiting everywhere, in severe pain and the left side of my face had dropped, I thought I was going to die. I was terrified, I had never felt anything like it in my life."
She recovered, however - and her scans stayed clear for three years. Then the cancer returned.
Tarrant would go under the knife twice more to remove tumour tissue from her brain. In 2014, doctors decided to try radiotherapy.
Tarrant described the eight weeks of radiotherapy, followed by six months of chemotherapy, as the most horrific thing she had ever experienced.
By February 2022, a scan revealed the cancer was back again - and growing fast. Doctors told her if they operated, there was a 90 per cent chance she would be left disabled. Tarrant was running out of treatment options.
But she eventually decided to go ahead with the surgery. Halfway through the surgery, doctors woke her up to see if she had lost any bodily functions.
"I couldn't move my left hand or leg. We terminated the operation, I told them it was enough, and I just cried," she shared.
Tarrant still feels numbness on her whole left side, and her left foot drags when she is tired. She'll meet with doctors again to decide whether to try chemo one more time, or if she should focus on the quality of her remaining life rather than trying to prolong it.
Her friends have created a GoFundMe to help her pay medical bills, living costs, and fund her passion project - a website where carers and people with cancer or cancer survivors can connect with each other.
She'll need about $50,000 to get it up and running, and her fundraiser has raised nearly $20,000.
Tarrant admitted she's "never been good at asking for help" but her friends begged her to let them start the fundraiser.
"I just want to be able to help as many people going through this as I can," she said.
"People don't understand how much brain disease, or cancer and the treatments impact your cognitive ability.
"Even things like speaking or thinking about simple things - or even moving your body become extremely taxing."
Tarrant hopes to raise awareness around brain cancer. In Australia, it has the least amount of funding of any cancer - and is the most expensive to treat.
"I was put on a cancer drug developed 30 years ago, I don't want other people to have to go through this, especially people who have to do it alone."
