The outspoken Nationals leader found himself in hot water in September when he threatened to blow up the coalition government if concessions weren't made on its koala protection policy.

Under pressure to quit and copping criticism from all sides, Mr Barilaro realised he'd been running on empty for a while and announced he would take four weeks mental health leave.

But the hits kept coming, with reports Mr Barilaro would lose his licence over speeding fines keeping him in the news.

Back from his break, Mr Barilaro said taking time off was the right call.

"It is never easy to admit that you have got a mental health issue and you are struggling and suffering," he told reporters on Wednesday.

"I remember being at home struggling to get out of bed."

But it wasn't smooth sailing for the coalition in his absence, with Premier Gladys Berejiklian weathering her own political storm over revelations she had a long-term secret relationship with former MP Daryl Maguire, who's at the centre of a corruption probe.

Mr Barilaro now says he's really concerned about her mental health.

"It's tough on the premier. I worry about her now," he told reporters.

"I support her 100 per cent. I feel for what she's going through."

He told Sydney's 2GB radio no one in parliament knew what Mr Maguire was up to.

"No one, not in a million years, would have guessed what played out last week, he said.

"Someone will write a book about it. I'm sure they'll even do a movie on it.

Mr Barilaro also revealed he almost impulsively quit parliament at an emotional NSW Nationals Party meeting.

"In the back of my head, I thought, 'Do I announce today? It is over. I can't do it any more'," he told reporters.

"If you asked me three and a bit weeks ago, it felt like I wasn't coming back."

While admitting his behaviour wasn't always perfect - and may have seemed erratic to some - Mr Barilaro said he had no regrets.

The koala policy stoush has since been resolved, with concessions.

Australian Associated Press