He was 10 years old when his mother showed him her cut wrists, gave him a penknife and asked him to do the same to his.

"I didn't know what to do. I was very scared, so I started crying," said Mr Lim Bo Zhi, now 24.

"After a while, she ended up crying with me."

He was then just a primary school pupil at St Joseph's Institution (SJI) Junior. She abandoned her attempt after Mr Lim and his father grabbed the knife from her.

His mother, a housewife, would attempt suicide several more times over the next few years, usually after a bad argument with his father over money, which petrified her young son, to whom she was very close.

Then one day, she succeeded.

Mr Lim and his father found her body hanging from the ceiling of her bedroom. He was just 14 years old.

"It was my worst nightmare come true," he said. "I was devastated and thought of taking my own life too to join my mum."

It never occurred to anyone that she had needed help for her depression. Instead, he blamed his father for her death, and grew to hate him.

"I felt that my dad had murdered my mother," said Mr Lim.

He stopped speaking to his father, who was a businessman, and shut himself in his bedroom most of the time, said Mr Lim.

He "lost all motivation to study" and dropped out of SJI.

Instead, he sought oblivion in computer games, and cut off contact with most people except his online friends.

He remained in a funk for two years, until a gaming buddy mentioned that he was starting university soon. "At that moment, I thought to myself, 'Wow, what am I doing with my life? I've been doing nothing,'" said Mr Lim.

Galvanised into action, he called his school counsellor and told her he wanted to return to school.

At first, school was overwhelming and he was tempted to skip it, but he slowly grew determined to excel in his studies. This time, he said, the memory of his mother was what spurred him on.

"My mother always wanted me to do my best, and I didn't want to let her down," said Mr Lim.

He moved into a boarding house when he was in Secondary 4 so that he could focus on his studies.

It was during this period that he slowly learnt to let go of his hatred of his father, who would often call him to check on him, so the two talked on the phone frequently.

By the time he had moved back home with his father after his O-level examinations in 2013, their relationship was back to normal.

Home life was peaceful for just a few months before tragedy struck again.

He had just got his O-level results, scoring 13 points, which he was very proud of, considering the long break he had taken from school.

But days after he and his father celebrated the good news, Mr Lim woke up one morning to find that his father, who was sleeping next to him, had died in his sleep.

He later found out that his father had been ill with pneumonia, but had not discovered this in time.

"I was very scared; I didn't know how to handle my father's death," said Mr Lim.

Worse was to come. Seemingly overnight, Mr Lim found himself alone in the world as his parents were not on good terms with their families.

The three-room flat they had lived in was taken back by his father's siblings as it belonged to his grandmother. Meanwhile, his father, who had debts from failed ventures, had not left him much money.

But Mr Lim was still determined to continue his education, and had decided on computer engineering at Singapore Polytechnic (SP).

His initial worries about paying the fees were eased by a trip to the student service centre, where student officers advised him to apply for bursaries and financial aid.

A kindhearted sponsor who heard about his situation through his school counsellor funded his stay at the boarding home for the next three years, and gave him a monthly allowance for his daily needs.

With his food, lodging and school fees settled, all that was left was for him to study hard - it would have made his parents proud. "I realised I could not fall back to the state I had been in in the past; I still had to live my life," said Mr Lim.

He excelled in his studies at SP and eventually won a Defence Science and Technology Agency scholarship to do a degree course at the Nanyang Technological University, where he is now a Year 1 computer science undergraduate. Home now is a hostel on campus.

His school counsellor from SJI, Ms Christina Tang, 52, said she has seen him blossom and flourish over the years.

"It hasn't always been easy for him; a lot of it has been two steps forward, one step back," said Ms Tang. "But all in all, we're proud to see how he has persevered, and how well he has done for himself."

Having been through so many ups and downs, Mr Lim hopes to encourage other young people who face seemingly insurmountable obstacles to seek help early.

"Reach out because there is always someone who is willing to help, so don't keep to yourself and suffer alone," said Mr Lim.

Apart from his SJI counsellor and teachers from SJI and SP, he has a group of close-knit friends from his polytechnic and secondary school.

Said Mr Lim: "It can seem easier to give up, but you should keep fighting because there is something worth fighting for at the end."

Correction note: This article has been updated to reflect the correct name of Defence Science and Technology Agency. We are sorry for the error.