Actor Samuel Johnson has opened up about his tragic life in an emotional episode of Anh Do’s Brush With Fame.

The Gold Logie winner almost brought ABC television host and comedian Mr Do to tears when he spoke of his sister’s cancer battle and his girlfriend’s suicide.

And the 38-year-old would go on to reveal another tragedy – the suicide of his mother when he was just three years old.

“I was too young to really gauge the effects of it, but she had all kinds of psychosis, she was in and out of institutions,” Mr Johnson said on the program.

The Secret Life of Us star said she tried “countless times” and her death brought some “relief” to the family, for her sake.

Mr Johnson’s life was again marred by suicide when his girlfriend, Lainie Woodlands, took her own life in 2006.

“I’m still very upset for her and for her family. I definitely say it’s probably my life’s biggest sadness,” he said.

“And in a way, the more time goes by, the more it hurts. You know how they reckon that you come to terms with your grief as you go along? Not with this one.

“With every year, it gets more profound, my sadness grows. We were young, you know.

“She had so much ahead of her, and she was a brilliant human.

“So, a great loss. A great loss. One that I feel a lot more profoundly than the loss of my mother.”

Mr Do appeared overwhelmed at the series of tragedies in Mr Johnson’s life.

“Sam, so you’ve lost your mum, your girlfriend, and now your sister is gravely ill,” he said.

“Do you ever think how unfair is life?”

But Mr Johnson almost laughed off the suggestion, and said he was not a victim.

“I don’t know whether I’m bullsh**ting myself or not, but I see my time with Lainie as a gift,” he said.

“Maybe I lost her earlier than I would have liked, but I had some of her.

I got to share my life with her. You don’t always get as much as you want of everything, you don’t get as much of your loved ones as you want. But you get them, don’t you?”

He is now facing the prospect of life without his older sister Connie, who was first diagnosed with cancer when she was 11.

The family raised more than $2.5 million for cancer research through their Love Your Sister foundation. Photo: Love Your Sister

“I looked over at my dad, he was just white,” Mr Johnson said in the emotional interview.

“He was curled up on the couch in the foetal position, sobbing. I really don’t remember life before my sister had cancer.”

Connie beat the first bout, before doctors found cancer in her womb when she was 22.

She overcame it, but the cancer has returned, and this time it’s terminal.

The mother-of-two has decided to withdraw from treatment and is farewelling her loved ones.

The family has used her last days raising money for cancer research, and on Sunday announced they’d pulled together more than $2.5 million through their Love Your Sister foundation.

Readers seeking assistance should contact Lifeline on 13 11 14.