Ellie Musgrave was 16-years-old when she first felt her chest 'collapsing inside her body' - with every breath she took, the space around her lungs became tighter and tighter.
Absolutely terrified of what was happening to her, Ellie sought medical help immediately and was later diagnosed by doctors with pectus excavatum - or sunken chest, as it's better known.
After everyday tasks became near-impossible, which saw Ellie fear for her future, she was finally granted surgery in 2018 to stop her chest from caving inwards.
But since her life-changing procedure, the operation has been classed as 'cosmetic' and was taken off the NHS in England, despite still being available in Scotland, Wales and Northern Ireland.
With the support of her surgeon, Ellie is now campaigning to make the operation available again on the NHS after it saved her life.
Speaking on ITV News, Ellie, from Carlisle, said: "When I was 16, I started having these episodes where I could literally feel my chest collapsing.
"I could feel the bones in my chest crumbling in, and I could breathe a little bit less each time I took a breath.
"And essentially what was happening is my chest was caving in more and more and I was losing more and more lung space."
At the start of her twenties, Ellie was "absolutely terrified" for her health and said "everything was getting worse" as the years went on.
She was unable to socialise with friends, play with her dog in the garden or get through her studies without worrying.
"By the time I had my surgery, I had 1.7 centimetres between my sternum in my spine. You're meant to have about 20/25," she said.
During the operation, metal rods were inserted into her chest to create more space and allow her to breathe again.
Ellie felt fortunate to have the surgery before NHS bosses deemed it 'cosmetic' - but argues that the suffering goes far beyond self-esteem.
Pectus excavatum affects one in 1,000 children and symptoms include rapid heart palpitations, chest pain, heart murmur, fatigue and dizziness.
Ellie's surgeon, Joel Dunning, said the decision to scrap the surgery from the NHS England was "disastrous" and a huge mistake.
He explained that the condition can cause "cardiovascular compromise" and the shortcut literature review did not consider people like Ellie.
A statement by NHS England said: "The current decision not to routinely commission this surgery is based on advice from doctors and a lack of clear clinical evidence to support its benefits.
"However, NHS England has reviewed its policy and arrangements are being put in place for those patients with very severe pectus excavatum, with symptoms beyond shortness of breath."
Do you have a rare health condition? Get in touch. Email nia.dalton@reachplc.com.