Renee Knight said she felt “sheer terror” when she became a first-time mum.

Within weeks of giving birth to her son Hamish in early 2016, Ms Knight began to slip into deep postnatal depression and anxiety.

“It started quite quickly,” she said.

“I worked out myself that I had it and I went from managing it at home to needing medical intervention really quickly.”

On the advice of maternity staff, she sought help at Werribee Mercy Hospital’s specialist mother and baby unit where she stayed for six weeks.

“I developed total insomnia,” Ms Knight said. “There was a horrendous period of time where I went 10 days without any sleep.

“You just feel sheer terror of being a mum.

“It’s soul sucking-responsibility is how I felt … feeling really unprepared for the unknown of parenthood.

“I went from being successful and career driven, living my life and desperately wanting kids.

“I had this expectation that the baby would do everything that the book said … and they just don’t.”

Over four months, Ms Knight stayed a total of 11 weeks in the mother and baby unit at Werribee Mercy receiving specialist acute mental health treatment and bonded with her son.

The unit operates alongside the Clare Moore building at the hospital, a 54-bed inpatient mental health unit at Werribee Mercy Hospital, which opened last year and is now running at its 54-bed capacity.

Ms Knight said the service “saved my life” and encouraged other mothers dealing with depression and anxiety to seek help.

“It’s a jewel in the community for mums,” she said.

“I went in as a shell of a person and came out as a mum looking forward to living life with my little boy.”

Hamish is now three years old and big brother to 10-month-old Fletcher.