That was until Mum passed away from cancer three years later. She was just 48 years old, and I really struggled to cope without her. So I was referred to a bereavement therapist to help me deal with my pain.
It was at the end of one of our sessions that my therapist asked a question that shocked me to the core. 'Natasha,' she probed. 'During the years Dr Collis treated you, did he ever touch you inappropriately?'
I took a sharp breath, taken aback. 'Yes,' I finally whispered. 'I think he did...'
My therapist handed me a tissue as tears sprang to my eyes. 'A receptionist at the surgery raised the alarm after a girl came forward saying he'd touched her inappropriately,' she said, explaining that he'd been suspended while police investigated the complaint.'
Oh my god. A sudden feeling of guilt, shame and anger hit me like a sledgehammer.
Fleeing the session in tears, I ran outside to where my dad, Michael, now 66, was waiting in the car. As my story tumbled out, he was devastated. How had our family GP hoodwinked me and Mum? I felt sick to my stomach.
In the weeks and months that followed, police officers carried out an investigation - but they didn't think there was enough evidence to prosecute. So, soon after, Dr Collis, a dad of three, resumed work at the surgery in Wadhurst, East Sussex. Life continued as normal for him.
Everyone saw him as an upstanding member of the community, someone to be trusted. But for me, it felt like I was living a prison sentence. Sinking into a deep depression, I found it really difficult to trust men or anyone in authority.
If I was sick, I'd refuse to go to the doctor. I much preferred to simply suffer in silence. Even so, I managed to leave school and head off to college, where I studied design. But wherever I went, my demons followed and I was plagued by nightmares. It wasn't until I was 19 that something finally changed.
I received a letter from the Fitness to Practise Panel of Britain's General Medical Council asking me if I would testify against Dr Collis. 'More girls must have come forward,' I gasped to Dad. And that's when I made a courageous decision. Even though I was in my first year of university, I knew I had to go back to Sussex to tell the panel about my experience.
I will always be so glad I did. Following the hearing, Dr Collis was held accountable for 43 instances of misconduct in relation to 'indecent' examinations, and he was then struck off the medical register.A year later, the police reopened their investigation too, and I gave them a signed statement to help their inquiry.
Over the next two years, the police collected evidence against Collis, and in June 2011 I finally had my day in court. Standing in the witness box, I refused to let Collis' piercing eyes intimidate me. It was tough though. Even after all these years, somehow he still had the ability to make me feel like a silly little girl.
But I wasn't an eight-year-old he could push around anymore. I was an adult - and I was going to have my say. In court, the prosecutors described me as their star witness as I bravely told the room he'd examined me internally 16 times over a four-year period - mostly right under my mum's nose.
After a two-week trial at London's Old Bailey, Antony Collis, then 59, of Stonegate, East Sussex, was convicted of eight counts of indecent assault against five children under the age of 14. He was also convicted of making indecent images of children.
'It's finally over,' I cried as I watched Collis get sent down after being sentenced to eight years and 10 months in prison. The judge said that Collis' conduct amounted to a 'gross breach of trust'. 'You've been very brave,' Dad whispered to me as we left the courtroom.
'I am really proud of you.'
I'm proud too. Because, two years on, I'm moving on with my life. I have a fantastic new boyfriend, Andy, 26, and I've graduated from university. Although Collis stole my childhood, I won't let him take the rest of my life too.