Last year I joined a company contracted to provide healthcare to asylum seekers. I made the jump from my old job with hopes of adventure and challenges which would not only make me a better nurse, but also a better person. Little did I know how much it would change the core of my being.

I first worked on Christmas Island as a mental health nurse. It was a real culture shock. I had always referred to the people I cared for as "patients", now I had to learn to call them "clients". I was quick to realise that the clients were often not even called by their names – they were instead called by the boat number displayed on their photo ID card, which had to remain on them at all times. "673/RYB/039!". The practice reminded me of stories from concentration camps in the second world war.

Things got worse as I took on other responsibilities across the island. One of the saddest places I worked at was referred to as "the induction shed". This is where asylum seekers are first led to after stepping onto the island's jetty. Once there they sit and wait, sometimes for hours, without any food or water. Once the bureaucratic paperwork is completed, and after they've answered questions by the department of immigration and signed consent forms, they're sent to meet someone like me.

As a mental health nurse, I would ask a series of questions outlined for us by the immigration department. These forms often asked unnecessary questions and avoided vital ones – we were told to "stick to the script". Time is of the essence, so we had to mill through the clients as quickly as possible.

It was there that I heard some of the most horrific and tragic of stories. Every day, I would be reminded of how evil humans can be to one another. I talked to a young Afghan man who was a Hazara ethnic minority. He has fled his country after a home invasion, where he witnessed his brother and father being murdered in front of him. He escaped, made it to a relative's home, and started his journey to Australia the next day. After experiencing numerous beatings and being shot at along the way he arrived in Indonesia, boarded a boat and took his chances. He was one of the lucky ones – he made it alive.

Another man I interviewed was from Somalia. Rebels had attacked his village one morning, burning houses down, beating and shooting people. He saw his mother being sexually assaulted before being murdered. The rebels then lined people up and shot every second person – the man’s best friend was standing next to him. The rebels told the remaining survivors to spread the word: it was their land now, and they would come back to finish what they had started if they didn’t flee.

The man's eyes welled up with tears as we told me his story. I asked him what made him happy, he replied "singing". So I asked him to sing – he interpreted an hymn, beautifully. Fellow asylum seekers from his boat were standing outside the room and started singing with him. Soon the hallway was alive with rich, raw and beautiful voices.

Surprisingly, my days spent in the induction shed were always the most desirable, because although you'd hear extremely sad stories, you would also be reminded of the strength of the human spirit to overcome tragedy and fight to survive. I often found myself in awe of the sheer tenacity on display. My "clients" were always so grateful to have made the boat journey, grateful to have a hot meal, shelter or water, and grateful to finally be safe from harm.

The hardest day of my career occurred early on during my time on the island. At the time, the Australian government was returning Tamils to Sri Lanka through a fast track process. This process only targeted Sri Lankans – no one else. They would arrive on a boat from Sri Lanka or India after spending up to 47 days on board, often running out of food. Upon arriving, they would be "fast tracked" through the induction process, which involved completing only a fraction of the medical tests. The next day, the "clients" would be woken up early in the morning, often around 4am, and told they would return to Sri Lanka that day before sundown.

The process was abhorrent. The asylum seekers would have no access to legal representation, and basic questions regarding persecution, torture and trauma were not properly investigated. This further frustrated me as I educated myself by reading about the Sri Lankan civil war and the mass killings which took place at the tail end of the 2009 war. I read Amnesty International reports and UNHCR reports detailing crimes against human rights: people going missing, civilians being sexually assaulted, imprisoned, beaten and murdered – all of which still happens to this day. The fast track process was a disgusting deal with the devil.

It was on one of these fast track days that I was called in to give support to a young man who had been told he was returning to Sri Lanka. I went into the room to find a young man hunched over the table, sobbing. Two burly security guards stood aside him with their arms crossed, steely faced.

He looked at me with desperation and told his story. He was 20 year old, from North East Sri Lanka. He had only arrived the previous day following a long boat journey. He told me that his distant uncle had been a fighter for the Tamil Tigers in the civil war. As a result, his father was harassed, targeted and eventually killed, shot in the family’s front garden by government police. He heard his mother scream, and heard the police enter the house. He ran and hid in a kitchen cupboard, where through the slats he witnessed his mother being sexually assaulted. They then slit her throat. The young man sold his deceased parents' property for enough money to get on a boat to Australia.

I will never forget the young man's eyes as he told me his story. He had suffered enormous trauma and immense pain at the hands of others. He was asking for safety, pleading for it. As a nurse I found it extremely difficult to comfort him. I couldn’t change the decision the department had made; in fact I was completely powerless. All I could offer was to listen to him, to validate him as a human being. To show that I had compassion for him. I told him to hold onto his faith, and that he was an extremely resilient person to have made it through this far. I told him that I cared, that I would pray for him.

When he looked up from his hands, I saw a face which will forever haunt me. It was the face of hopelessness. He was empty, numb with despair. He said "I am going to die. I did nothing wrong and now I am going to die. All I wanted was for Australia to give me safety". The boy was led away onto a bus to transport him to a plane bound to Sri Lanka, where he would be handed over to government officials.

I often have thought about that day and asked myself how I can come to terms with my role in this process. The way I see it, if I wasn’t here doing this work, then who would show these people compassion? Who will listen to their story? Who will validate them as a person, and not a number? As horrible as the process is, I'm proud of what I have been able to offer the people.

Since returning from Christmas Island, my friends from school often ask me about my experience while at the pub. "Are you still helping support those bomb throwers?" they ask, adding that refugees are " taking our jobs". I feel a strong burning inside each time, and want to scream at them for showing such ignorance. But instead I tell them the story about the guy from Somalia, or the boy from Afghanistan. And when they listen, they see what I see. I give them information and facts, and it makes them think. That’s all I ask of people when it comes to the asylum seeker issue: just think about it, read more about it. Don’t take for granted that the government is doing the best thing.

I am by no means naive enough to believe that every person I met is a genuine refugee. I have seen my fair share of people whose motivations I have questioned. But the huge majority of the asylum seekers I have interviewed have gone through horrific trauma and torture, and have fled or been driven out of their own country. They come here to save their children or themselves, only asking for safety.

I truly believe that most Australians would show much more compassion and understanding if they experienced what I have. I have never been ashamed to be Australian until I was thrown in this process. I have also never been so thankful to have won the lottery: to be born in this country, free from war and terror.

• The writer is using a pseudonym