"I've always been told I'm not scared of anything, but this MS terrifies me," Livvy admits. "I feel so small."
The 38-year-old has lived an edgy life, producing and presenting documentaries on topics from girl gangs to child soldiers in the Congo. Her latest hit is Gangster: The story of John Palmer for BBC Sounds, which investigates his involvement in the 1983 Brink's-Mat gold bullion robbery - the largest armed robbery in British history.
It was her love of American rap music as a teenager that formed her fascination with the criminal underground, gangs and violence.
"I wanted to understand it," she says. "A lot of the time, people who are committing crimes don't get to talk about it from their perspective."
It has helped her understand what motivates them to take such risks - and how sometimes the choices can appear "logical" to them.
It was while Livvy was investigating the war on drugs in the Philippines in 2016 that a plot twist in her own life began to unfold.
"There was something really wrong with my legs," she tells BBC Access All. "I was sure it was dodgy food."
Livvy finished her film and returned to the UK, but the symptoms persisted. Over the next four years she made several trips to the doctor but never got a diagnosis. In 2020 it was suggested she undergo a lumbar puncture - a test of her spinal fluid - to "rule out MS". But the result confirmed the very opposite.
MS occurs when the protective layer surrounding nerve fibres - myelin - becomes damaged and stops messages flowing between the brain and body. It can affect the spinal cord and impact vision, movement and balance.
After a call from a neurologist confirming Livvy did have MS, she was told she would receive another phone call, within the week, to plan her treatment. But weeks passed and no phone call came, all while she was trying to hold it together. "It was like I'd been given a grenade," she says.
She distracted herself by focusing on the documentary she was working on about kidnap gangs - "It was easier to think about," she says.
But by Christmas, "the grenade exploded", and a minor family disagreement turned into "something out of EastEnders".
The nurse did eventually call, and when Livvy started to process the diagnosis she knew she would have to consider her future very carefully, especially when it came to her dangerous investigations.
She's lost count of the number of freezing nights she's waited outside for dealers to appear for interviews. "They're the most unreliable people in the world," she jokes. She often tells late-comers off for the pain they have caused her.
But her work has also been her salvation - not just as something she can lose herself in, but as an unlikely source of support and empathy.
"I come across lots of disability within the world of crime," she says. "At one point the majority of the gang members I interviewed were either in wheelchairs or had ongoing medical issues from gunshot wounds."
Sickle-cell disease is one disabling condition she comes across frequently. It causes red blood cells to distort and become sticky, blocking vessels and restricting oxygen supply, which triggers excruciating pain.
One of her contacts was receiving treatment for it in hospital when he became the victim of a honey trap. A rival gang sent him Instagram messages, pretending to be a woman and saying how "hot" he was.
"He's in the hospital and says 'Come see me,' so the rival gang went to see him in hospital and attacked him. It was outrageous," she says.
Another of her favourite contacts to talk to about life with a disability is a reformed gang member based in the US. At the height of his notoriety he ran 30 drug-houses in Dallas. Then his gang turned on him.
"They shot him in the head - that bullet went straight through both optic nerves and they left him to die. He somehow managed to get up, and he's now completely blind," she says.
Some of the criminals Livvy speaks to are also carers for their disabled friends and family.
"So many youngsters are looking after their parents. I won't justify their crimes with it, but it's having that insight into what is pushing them into needing money," she says.
Livvy's MS affects her legs, vision and she gets shooting pains down her sides like "electric shocks" - a well-known MS symptom.
She can also struggle with finding the right words - "I end up saying bizarre sentences because the messages in my brain don't work."
Her treatment involves an infusion every six weeks to help reduce the amount of damage and scarring to the myelin sheath.
The condition has also raised other issues she wasn't expecting to confront, like whether to tell prospective partners about her MS.
"It's hard enough trying to date," she says. "I want to meet someone and settle down, but this feels against me."
As a freelancer, she's now having to rethink her life-plan and career, to ensure she manages her money, health and safety in her unusual job.
"It's a tough industry and I'm always scared to take time off," she says. "You don't say no to jobs because you worry they won't ask again."
But even if her career does take a different turn, she plans to continue confiding in her contacts who understand what she's going through.
"There's a gentleman I know who spent an awful lot of time in prison and actually fell off his bunk which caused horrendous injuries to his back. We talk quite a lot because we can relate so much.
"It's quite funny, we go from talking about robberies to 'How's your health?'"