Wife Kosha said: “he studied hard, he parented hard, he partied hard and he felt hard”.

And, in the end, it was the feeling hard that caused the much loved father of two, former soldier and Ballarat fireman to take his own life last week, aged just 40, after suffering from post-traumatic stress disorder for several years.

Last year, Nathan walked 400 kilometres from Mildura to Adelaide to raise PTSD awareness.

A large crowd of mourners gathered at the Wendouree Centre for Performing Arts on Friday to pay tribute to the man described as “having as many nicknames as he had postcodes”, including Nath, the Mule, the Tank, the Big Fella and Daddy.

A guard of honour was formed by firemen from Ballarat, his former stations Mildura and the Northern Territory Fire Service, and soldiers he served with in Darwin and the Solomon Islands.

Stretching a long way down Howitt Street, Nathan’s coffin – borne on an antique fire engine – was saluted by the honour guard as it made its way to the Buninyong Cemetery.

Nathan was born on April 17, 1976 and attended Clunes Primary School and St Thomas More before “majoring in truancy” at St Patrick’s College.

He managed hotels across Australia, including the Subiaco Football Club function centre, before enlisting in the Australian Army on January 10, 2005.

Nathan was described as a skilled marksman who trained in Darwin before serving in the Solomon Islands.

He was only days away from his dream of joining the SAS when he voluntarily withdrew from the Perth-based program to help Kosha nurse their ill baby daughter Lila for six months back in Darwin.

However, his service in the Solomon Islands exacerbated existing mental health problems and he was described as “one person dealt too many hard hands”.

Cousin Drew Parkinson said Nathan fought his PTSD demons bravely.

“He hid his pain and suffering and put on a brave and courageous face to keep us all happy,” Mr Parkinson said.

During his eulogy he also pleaded with governments and bureaucrats to “please find the courage to act” on the issue of mental health problems in former veterans.

Another cousin, Xavier Shanahan, described Nathan as a “person of exceptional courage and bravery – that was you to the letter”.

Mildura senior station officer Malcolm Hayes said “Shannas” was king of the gym and thought he was king of the ping pong table.

Mr Hayes joined Nathan’s Walking Off the War Within trip last year and said he was “battling demons no-one else could see”.

“He fought those demons and he stood his ground,” Mr Hayes said.

“From the time the walk started it was evident that something special was happening.”

He described a B double truckie stopping them on their trek and shaking Nathan’s hand.

“He said ‘thank you for bringing this subject up, I’ve suffered with it too’. This happened every day.

“It’s a hidden illness that everyone’s touched by and he brought it to the forefront.

“He touched thousands of people’s lives and probably saved their lives by doing so.”

Ballarat City firefighter Josh Martin said Nathan was “one of us from the day dot” when he arrived at the station earlier this year.

“He was open and honest about his struggles, his ups and downs, his good days and his bad days,” Mr Martin said.

“We could not have had any more respect for him as a firefighter and as a person.

“Nathan Shanahan is one of us. He is like a brother to us. He is a legend of a bloke and he will always be with us.”

John Shanahan is now a man on a heartbreaking mission.

He doesn’t want any other families to endure what his has over the past week after his only son Nathan died by suicide on December 22 after a long battle with post-traumatic stress disorder.

“I want to make sure if we yell and scream enough, more is done about it,” Mr Shanahan said.

“We’ve got to start looking at this issue very seriously.”

He said he now planned to become a passionate advocate for more mental health funding, particularly for PTSD, with one in eight men suffering from anxiety and depression and 72 per cent of males not getting help because of the fear of talking about it.

Mr Shanahan has also asked for any donations in Nathan’s memory to go to Soldier On at soldieron.org.au, which helps with the physical and mental well being of returned services personel.

If you need help, contact Lifeline on 13 11 14