Watch a report by ITV News Anglia's Russell Hookey
A teenager with epilepsy is one of the first to be given free medical cannabis following a campaign to get the drug given to more people with the disease.
Harry Siddans, 15, from Dunmow in Essex, has refractory epilepsy and has been using medical cannabis for two and a half years.
His parents say the drug stops Harry's seizures, which are constant, and allows him to walk and go to school.
Marie Siddans told ITV News Anglia that the drug is a life changer.
"It got to the point where Harry was unable to walk, he was just lying lifeless, dribbling, eyes rolling back on his head," she said.
"We were literally moving him room to room on a duvet. It was really tough.
"The thing is when you start it [the drug] there's no going back."
The medical cannabis had been costing the family £995 a month until Mrs Siddans got in touch with campaigner Charlotte Caldwell on social media.
"I think we've spent over £30,000 and it's worth every penny to find that money, even though it's a struggle because you see the difference it makes in your child."
Ms Caldwell launched her "I am Billy" campaign after her son Billy's case changed the law on medical cannabis in 2018.
Billy's story hit the headlines after Ms Caldwell flew to Canada to get a new supply of cannabis oil for her son, which was seized at customs on her return.
Billy's health deteriorated and he was taken to hospital suffering "life-threatening" seizures, prompting the Home Office to grant him an exceptional licence to use the cannabis oil medicine.
Earlier this year Ms Caldwell helped set up a scheme where some global cannabis manufactures agreed to give free medical cannabis to epileptic children if their medical data and outcomes could be shared with doctors.
Harry Siddans is among those taking part in the scheme - meaning his medication will no longer cost a penny.
Mrs Siddans said: "It's incredible and I am truly grateful to Charlotte for putting out there what us parents can do because you do feel very lonely and isolated and you come to expect this is what life is going to be."
Their daughter Rose, 13, also has a rare genetic condition, so she too has multiple daily epileptic fits and significant cognitive disability.
The condition called Adenylosuccinate lyase deficiency, an inherited metabolic disorder, was only diagnosed three years ago by Great Ormond Street Hospital.
The diagnosis helped the Siddans to understand why Harry and Rose's seizures were so difficult to treat with conventional medicines.
Thankfully the drug manufacturer has now offered to provide the cannabis medication free of charge for Rose thanks to the Caldwell scheme.
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