The Smith Street Band frontman Wil Wagner has published a lengthy statement addressing allegations of emotional abuse, admitting he’d said “incredibly hurtful things”.

In the wake of allegations of “harassment and emotional abuse” made by his former partner Georgia McDonald – the lead singer of Camp Cope – Wagner issued a statement saying he had “expressed myself in a way that I completely regret and I wholeheartedly apologise for” and was “trying to be a better person”.

McDonald issued a public statement last month following the circulation on social media of emails and messages sent by Wagner. In it, she revealed she was the recipient of some of the correspondence, and accused Wagner of harassment following their break-up.

On Thursday Wagner announced the band was cancelling its upcoming tour after a string of support acts pulled out following the allegations, and addressed the allegations.

“The private emails were written almost three years ago at an incredibly low point in my life at the end of a long-term relationship with someone I loved and cared for very deeply,” he said.

“Towards the end of the relationship and after we broke up, I was heartbroken and hurt, depressed and angry.

“As a result, I said some incredibly hurtful things that I should never have said and expressed myself in a way that I completely regret and I wholeheartedly apologise for.

“I am embarrassed that everyone has now seen me at my absolute worst.

“Our relationship had very big highs and also very deep lows. It could at times be a toxic relationship. We could speak lovingly to each other and also horribly to each other. I take my share of the responsibility for the toxicity which existed between us. And I apologise to my former partner for my part in the hurt caused.”

Emails to McDonald and Facebook messages to another woman had been circulating on social media in the lead-up to her statement, which was pulled down after lawyers acting for Wagner sent legal notice letters to her, Guardian Australia and a number of other media outlets.

Wagner said in his statement that they were published “in breach of confidence and in breach of my privacy”.

“Omitted from the correspondence were responses by both me and my former partners,” he said.

“They were small snippets of two-sided correspondence and conversations within two different relationships.”

In her statement McDonald alleged that Wagner had threatened her during their last contact “the night before our last album launch”.

“This is why people don’t come out about abuse.”

“[He] threatened to kill me and then himself,” she wrote. “I have screenshots.”

Guardian Australia has seen a copy of the text message in question.

But Wagner said the alleged threat was “nothing of the sort”.

“It’s a reference to a stupid, dark, long-running joke my former partner and I shared,” he said.

“It stemmed from slightly goth/emo and perhaps wannabe minds claiming we had a ‘Kurt and Courtney’ or ‘Romeo and Juliet’ type of connection.

“A kind of self-destructive love/hate relationship, which could only end badly. We joked about this subject often. It was completely lame, plainly in poor taste and is utterly embarrassing. But it carried no intent or menace from either of us.”