Former Silverchair frontman Daniel Johns has shared a statement following his conviction for drink driving.

Last month, it was revealed that the 42-year-old Johns had entered rehab after being charged with high-range drink-driving after a collision with a vehicle in the Australian New South Wales Hunter region. He then plead guilty to the charge and could face jail time.

In a new post on Instagram, transcribed from a phone call with Johns from his rehab facility, he said: “My drinking had become a bigger problem than I even realised, and how I have used it to help numb a range of deeper psychological issues that I’ve been living with since childhood; Alcohol is not medicine. I should never have treated it like it was. I feel like a complete fuck-up and I’m sorry.”

The post added: “I take full responsibility for my actions on the evening of March 23rd, I am deeply remorseful and I am working every day to make amends.

“I am handling these matters professionally and privately. For legal reasons, I am unable to talk specifics on social media or elsewhere until after June 22nd.”

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A post shared by Daniel Johns (@danieljohnshq)

“Alongside my therapy, I’ve been self-medicating with alcohol to deal with my anxiety and depression. I know this is not sustainable or healthy,” he wrote in March.

“I have to step back now as I’m self-admitting to a rehabilitation centre and I don’t know how long I’ll be there. Appreciate your love and support as always.”

Johns was absent from the court hearing on April 11 in the Hunter region, with his lawyer entering a guilty plea on his behalf.

As The Guardian report, Johns’ lawyer Bryan Wrench asked magistrate Ian Cheetham to hand down sentencing immediately due to the mental toll the trial may take on Johns, but Cheetham told the local court in Raymond Terrace that the offence was too serious in nature for this to be a possibility – and that Johns may face a prison sentence.

The case has now been adjourned until June 22. “His main focus is his mental health,” lawyer Wrench told the court of Johns.

A police report cited by The Sydney Morning Herald at the time of Johns’ charging said that the singer had been driving an SUV northbound on the Pacific Highway when his car allegedly collided with another vehicle travelling southbound.

A roadside breathaliser test conducted by attending paramedics allegedly returned a positive result. New South Wales Police said: “[Johns] was arrested and taken to Raymond Terrace police station where he underwent a secondary breath analysis which returned an alleged reading of 0.157.”

In an Instagram from the time of the incident, Johns addressed his ongoing management of his mental health. “As you know, my mental health is a work in progress. I have good days and bad days but it’s something I always have to manage.”

Johns said that over that week, he began to experience panic attacks. He continued: “Last night I got lost while driving and I was in an accident. I am OK, everyone is OK.”

The artist was vocal his mental health struggles in the Spotify podcast Who Is Daniel Johns? in which he opened up about his battles with anxiety disorders, depression and anorexia.

News of his accident came just a day after he announced a new philanthropic endeavour, FutureNeverFund, which aims to help “people and animals who would never have a future if not for some financial intervention”.

His second solo album ‘FutureNever’ is due for release on April 22.

For help and advice on mental health:

• ‘Am I depressed?‘ – Help and advice on mental health and what to do next

• Help Musicians UK – Around the clock mental health support and advice for musicians

• Music Support Org – Help and support for musicians struggling with alcoholism, addiction, or mental health issues

• YOUNG MINDS – The voice for young people’s health and wellbeing

• CALM – The Campaign Against Living Miserably for young men

• Time To Change – Let’s end mental health discrimination

• The Samaritans – Confidential support 24 hours a day