Vanessa Boyd, 28, saw at least 30 different health professionals from age 16 with a number of different symptoms including vertigo, dizziness, fatigue, insomnia, blurred vision, bleeding from the ear and numbness.
She claims she was told she had generalised anxiety disorder and depression.
It wasn't until she researched the symptoms of Lyme disease and requested a private test for the tick-borne illness that she was diagnosed with it in July 2015.
Following further tests, Vanessa discovered she had late-stage Lyme disease in September last year, was given a month of treatment and told the NHS could manage her symptoms.
Vanessa said: "Current treatment in the UK for late stage Lyme disease is outdated and known not to work in its later stages.
"I had the 'gold standard' treatment in the UK in 2015 with no sustained improvement to my health.
"My prognosis, had I stayed here, was to become increasingly disabled with time."
Vanessa made the decision to leave her family and friends in the UK and travel to America with her partner Laura Wake, 34, where she has paid £60,000 for a nine-month course of private treatment.
Her father, Roy Boyd, 69, is preparing to sell his house to help fund his daughter's treatment.
Vanessa, who is now based in America until next September, said: "One of the worse parts of this whole process is that Lyme disease is entirely treatable if caught early.
"The NHS website says the disease can be treated effectively if detected early on.
"I went to my GP with a rash all over my legs and under one arm when I was 16. This was misdiagnosed as impetigo and there followed 12 long years of serious symptoms being misdiagnosed and overlooked."
Around 10 weeks after Vanessa went to her GP with a rash, she was admitted to A&E with a severe headache and this was believed to be viral meningitis - a diagnosis Vanessa was unaware had even been given until she requested her medical records in 2014.
She said: "What we now believe is that that was actually Lyme meningitis which is when the disease moves into the brain.
"I was sent home with no treatment and no follow-up."
At 21 years old, Vanessa began showing neurological symptoms including conscious seizures, shortness of breath and palpitations and she now knows she was going through progressive brain damage.
At age 22, her left ear went numb for three months and no explanation was given. Around the same time, Vanessa, from Dronfield, Derbys., underwent a brain scan that showed signs of brain damage.
She said: "At the time of that brain scan, my GP told me that I was most likely born with the brain damage.
"But I now know that I had a brain scan at the age of 16 that showed no brain damage and my GP would have had access to this in my medical records."
In 2014, Vanessa's symptoms worsened and she started to suffer from full body convulsions, head throw backs and tremors - all signs of problems in the brain.
Vanessa, a civil engineer, said: "The GP was taking my complaints on a symptom-by-symptom basis.
"When I started to deteriorate, they should have looked at all of my symptoms together.
"In 2015, I was seeing a neurologist, cardiologist, ENT specialist, ophthalmologists and I was deteriorating quickly. If they had put it all together, they might have realised what the problem was."
As a result of the damage already done to her brain, Vanessa has had to give up work, can't watch TV or look at computer screens and can no longer be in busy, visually stimulating environments.
She said: "The impact on my life has been catastrophic. I've lost my social life. I had to get a boat to the USA as I can no longer fly due to the inflammation around my brain.
"I can't have hot baths because my body can no longer regulate its temperature and I suffer from sleep apnea which means my brain forgets to tell my lungs when I'm asleep so I'm periodically woken up gasping for air.
"I can't drive because I get vertigo and my memory has become very poor."
Vanessa added: "All of these symptoms as they began to appear were passed off as anxiety problems.
"I was told my difficulties driving were due to anxiety, the seizures I had and my shortness of breath and palpitations were panic attacks.
"What is more likely is that I was suffering from inflammation around the brain."
At first, Vanessa fought against the idea of anxiety and depression but the more she was told that was what it was, the more she began to believe it.
She said: "When my GP diagnosed me with generalised anxiety disorder, the first thing I said to them was that I'm not an anxious person - depression didn't make any sense to me.
"But I was told that that was the problem and I started to believe it.
"I went through everything to try to solve that diagnosis - I took antidepressants, I went for Cognitive Behavioural Therapy and I even paid for a hypnotherapist because I wanted to be able to fly.
"I was referred to the mental health services in hospital and I went to one session but throughout the time I was there I knew that wasn't what was wrong with me."
Vanessa stayed with her GP surgery up until 2013 but saw a number of different doctors within the same practice who continued to diagnose her with the same thing.
Vanessa added: "I gave my all to get better when I thought I had depression but I couldn't get better because it wasn't the right diagnosis.
"Because I was told I was depressed, I tried to force myself to do more things - I completed my civil engineering degree part-time while I worked and tried to carry on as much as normal.
"But actually, I was living in hell and having symptoms of a very serious disease all by myself because I felt too embarrassed to admit to anyone that I was suffering from depression.
"I lived a normal life right up until 2014 when I began to seriously deteriorate and things got really bad.
"I thought I was going mad at the time. Over night my vision changed and I couldn't see anything.
"I got a sudden onset of numbness and my new GP referred me to a neurologist and asked me to keep in touch with them - they knew that there was something else wrong."
Now in America, Vanessa feels like she has a final chance to get her life back.
She said: "I am being treated to cure the actual disease and not just with symptom management.
"The specialist, Dr Jemsek, has told me it is time to fight for my life but he anticipates a favourable response to treatment in my case."
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Facts About Lyme Disease
Vanessa's partner of eight years, Laura, has given up her job as a university lecturer to travel out to America to be with her and has been trained to administer her medication.
Laura said: "Vanessa has had to fight for treatment and testing at a time when she is so ill she often can't see or feel the ground under her feet.
"We have met some good doctors in the UK more recently, but the ones who have dismissed, missed, and overlooked such serious symptoms are a real danger to people with diseases that are under the skin.
"I've already had to watch Vanessa deteriorate over the last seven years but I'm lucky that Vanessa trusted her own body, never gave up and is determined to get better."
Vanessa thinks that more should be done to look out for Lyme disease by GPs.
She said: "It took me 12 years to see an infectious disease specialist - that is outrageous.
"GPs should be on the look out for the early signs of Lyme disease, when it can be stopped in its tracks, so that other people don't end up like me.
"It simply isn't good enough to say, 'there is nothing more I can do for you' when there are cases of later stage disease recovery in the US. If it can happen for one, it should happen for all."
A fundraising page has been set up for Vanessa's treatment. To donate, visit gogetfunding.com.