Child victims of sex abuse within families are being let down by the system, new research has warned.
Young people are often left to report the abuse themselves when authorities fail to pick up on signs, a series of reports found.
Even after their experiences are disclosed, investigations into sex offences against children often take "considerably longer" than those against adults, the Children's Commissioner for England said.
Victims also often face long waits for therapy, the research showed, and many are blocked from having counselling in the run-up to their court cases.
Abuse within family environments is thought to make up two thirds of all child sex abuse, and as few as one in eight victims come to the attention of authorities, previous research by the commissioner's office found.
Some abuse survivors have now told how they felt "abandoned" after telling their families about the trauma they had suffered, and in powerful testimonies they spoke of their frustrations at a lack of support.
The commissioner's office released three reports on Thursday, looking at how abuse is investigated, the role of schools in preventing child sex abuse and things to be learned from survivors.
One 19-year-old woman said giving video evidence was "like it's (the abuse is) going on again, the whole thing's happening again".
Researchers from the University of Bedfordshire, in partnership with the NSPCC, spoke to young people aged between five and 19 about their experiences of abuse within a family setting.
Using information from the Home Office and Crown Prosecution Service, the commissioner's office found that a rise in sex offence reports was placing a strain on the justice system.
Investigations into child sex abuse can take an average of 100 days longer than adult cases, the reports found.
While many teachers feel confident they can recognise the signs of abuse, schools are not always fulfilling their potential roles in preventing incidents by educating children about seeking help, one of the reports said.
Children from the age of four upwards will be taught about healthy relationships and sex education will be come compulsory in all secondary schools from 2019, the government announced earlier this year.
Anne Longfield, Children's Commissioner for England, called for urgent changes to the system, looking to the approach in Iceland, where child victims are offered specific services to deal with their trauma.
She said: "It is clear from this research and the heart-breaking stories told by young people within it, that many child sexual abuse victims are being let down by the system."
She added: "Professionals remain dedicated to supporting the victims of abuse, but urgent changes need to be made to the way it is reported, the role of schools in preventing it and the criminal justice process in child sexual abuse cases.
"The Icelandic 'Barnahaus' approach, where services ranging from medical examination to therapy are provided to victims under one roof, has been proven to be successful in overcoming some of these hurdles and I hope it will be trialled in England."
Dr Camille Warrington, from the University of Bedfordshire and lead author of the Making Noise report, said: "We know that child sexual abuse flourishes in cultures of silence.
"Undertaking the Making Noise research project highlighted only too well children's own appetite and ability to help break that silence.
"It also emphasises the need for us as adults and professionals to improve the way we listen to and talk with children to prevent and respond to abuse - and the benefits that come from doing so."
Barnardo's chief executive Javed Khan called for compulsory lessons in schools to include topics like "sexting", consent and online grooming.
He said children should be assigned an independent advocate to help them navigate the court system when their abusers are brought to trial.
He added: "We hear every day how much children and young people at risk of, or who have experienced, sexual abuse need and benefit from our specialist services, but we know many more need our help too."