An inquest has heard that a teenager researched suicide online before taking his own life after years of bullying.

Ayden Keenan-Olson, 14, was found dead in his bed by his father, Tim Olson, at the family home in Colchester, Essex, at 7.20am on 14 March. He had taken an overdose of prescription drugs and left two suicide notes outlining the homophobic and racist bullying he had experienced at Philip Morant school, an inquest in Chelmsford heard.

Ayden's mother, Shy Keenan, an author and prominent child abuse campaigner, said he had been "bullied to death". A police investigation found that in the month leading up to his death Ayden had bypassed settings on his computer to research suicide methods on the internet.

Keenan told the inquest: "My job is to protect kids online but I could not keep my own son safe."

The Essex coroner, Caroline Beasley-Murray, recorded that Ayden's death was the result of suicide. The inquest heard that Ayden had attempted to take his own life six months earlier. The family believe he took prescription drugs from home and hid them at school.

The school's headteacher said Ayden had reported up to 20 incidents of bullying since joining the school. Beasley-Murray said it was not her job to attribute blame and she made no finding regarding bullying or the school's conduct.

Referring to suicide websites, the coroner said: "The court regrets the influence that such sites have on young people. He clearly was much loved and had so much going for him and I hope you can look back on the happy memories that you have of him."

Keenan told the hearing that her son had been bullied for several years and attempted to take his life in October last year.

Breaking down in tears during her evidence, she said her son had been targeted with violence, abuse and malicious allegations because fellow pupils believed he was gay and because he had part-Japanese ethnicity.

Shortly before Christmas he had told his family he thought he was gay. Keenan said: "He said he was gay and had found somebody he thought he loved but it was not reciprocated. We didn't care, we just loved him whatever. After Christmas it was like talking to a different boy – since he was able to say out loud to people that he was gay."

She described Ayden as a sensitive child who had planned to start his own anti-bullying campaign. He was a keen musician and idolised the television presenter Gok Wan. "People would call him Gok as a compliment," she said. "He tried very hard to look like him."

The school's acting headteacher, Robert James, defended its policies for dealing with bullying. "As a school, our first priority is to make sure our students are safe," he said.