Callum Hancock was 10 years old when he was raped by a longstanding bully in a den in his back garden. “They made it sound like a game, they said it’s like smoking, something you do when you’re older, that if you tell your parents you’ll be in trouble.”

Speaking in a broad Sheffield accent, the well-built 28-year-old recalls having loving parents and a happy childhood – “plenty of holidays, lots of laughter” – punctured by trauma. Later, as puberty crept along and girls caught his eye, he wondered if the attack meant he was really gay. He started to ask himself if maybe he’d dreamed it: anything to suppress what had happened. He took up boxing because it “was my way of proving that I was a man, that I was going above and beyond to prove I was a man”.

But he felt consumed with rage, rage that would get him into trouble: at 23, he was jailed for assaulting a bouncer. “I needed help,” he tells me. “I was either going to kill myself or kill the perpetrator – or both.”

Male rape and sexual abuse is a largely hidden crisis. We know most female survivors never report their experiences; among men, it’s even higher. For those men who do come forward about sexual abuse, the evidence suggests that it takes them three decades on average to do so.

Last week’s sentencing of Reynhard Sinaga – the most prolific convicted rapist in British history, who preyed on largely straight men in Manchester, lit a momentary flare. But as the light fades and the case assumes its place in the catalogue of Britain’s worst crimes, the danger is that a wider conversation won’t be had: about the lack of support for male survivors, and how toxic gender norms leave them traumatised and struggling.

A mile away from where Sinaga committed his crimes, Survivors Manchester – a charity dedicated to male survivors – is holding a symposium. Its CEO, the charismatic Duncan Craig, founded it more than a decade ago, launching it with a website he made on Microsoft Word. For Hancock, its support was life-changing – “lifesaving, even” – but it wasn’t always easy: when he spoke publicly about his experience on the BBC’s Victoria Derbyshire show in 2018, he was inundated with messages from other survivors. Supportive as they were, Hancock had not processed his own trauma. He could not speak about it in the first person – “it was ‘you feel guilty, you feel ashamed’. I was living numb.”

Society drills strict gender norms into boys’ skulls from a very early age: a sense of being “strong” and “tough”, of not displaying weakness or vulnerability. It’s something Hancock touches on: “I’d always worn a mask, I always wanted to put on a brave face and be there for others. Showing my vulnerability, my weakness, wasn’t within my character.”

When it comes to male rape, gender norms collide with trauma: many survivors feel guilt or shame, torturing themselves with questions such as why they didn’t somehow fight off their attackers, or wondering if there was some hidden vulnerability that had caused them to be targeted. Myths become formidable obstacles to survivors confronting their traumas: that “real men” don’t get raped, that survivors of rape or abuse must be gay, that rape is about sex rather than power and control, or that the abused are likely themselves to become perpetrators.

As Alex Feis-Bryce, head of SurvivorsUK – himself a survivor who, aged 18, was drugged and raped like Sinaga’s victims – puts it: “A lot of men feel completely emasculated after being raped. That’s what silences them for so long.” Add in the fact that men are taught that talking about feelings and emotional struggles is somehow unmanly, and it’s little wonder that many survivors are driven to damaging self-medication, such as alcohol or drug abuse, or, like Hancock, they end up incarcerated.

As Craig – who was abused from the age of 11 – tells me, men do want to talk, “but they just need to be told it’s OK”. It’s up to his team to overcome entrenched gender norms by providing survivors with stability, making them feel safe and allowing them to process what they’ve gone through and have meaningful lives.

For some survivors, the process takes longer than others and noteveryone seeks the same experience. Many prefer to talk by phone: as Neil Henderson, the CEO of Safeline, a male survivors’ helpline, told me: “It’s the disinhibition effect, that if you tell me something I’ll react even if I try not to, but you can’t see a reaction on the phone.”

For some, that one phone call is enough: just to receive validation that they are not to blame, that it’s not their fault, that they’re not abnormal. When high-profile cases happen, the numbers surge: in the aftermath of the Sinaga sentencing, calls jumped by 5,000%. Some have carried the burden for so long: at the end of last year a 93-year-old phoned to talk for the first time about being abused as a six-year-old.

The work done by such organisations transforms lives, but there are no statutory services for male survivors and male rape is subsumed into the government’s violence against women and girls strategy. The funding and resources aren’t enough, and so there’s a postcode lottery. While a Mancunian survivor has an organisation to turn to, what about so many in small towns, let alone the countryside?

And here, again, we see the consequences of gender norms imprisoning men: in the UK the biggest killer of men under 45 is suicide, often because they feel unable to get the support they need. “To support boys and men, we need to adopt a new language: that it’s OK to be vulnerable,” Craig tells me. “I know now my own vulnerability is my strength … that holding it means no one else is holding it against me. It’s my weapon to cut through dark times.” Male survivors are suffering, largely in silence: but it’s not because they don’t want to talk. How we build a society that frees them to do so: that is the challenge we must all answer.

• Owen Jones is a Guardian columnist

• In the UK and Ireland, Samaritans can be contacted on 116 123 or email jo@samaritans.org or jo@samaritans.ie. In the US, the National Suicide Prevention Lifeline is 1-800-273-8255. In Australia, the crisis support service Lifeline is 13 11 14. Other international helplines can be found at www.befrienders.org.