When South Sudan gained independence three years ago it was probably one of the happiest days of my life. Africa's youngest nation - my home - was full of optimism and hope.
I was there in Freedom Square in the capital, Juba, celebrating with my parents, my siblings and my countrymen and women. It was an unbelievable feeling. Everyone was excited, with people speaking of a promising future ahead, of prosperity and harmony.
But now as the third anniversary of the nation's independence approaches, that optimism and hope has turned to despair and fear as the reality of months of brutal conflict takes hold. I knew the road ahead for South Sudan would be difficult after decades of war, but I never thought it would be like this.
Since last December when fighting broke out, tens of thousands of people have been killed, almost 400,000 have fled to neighbouring countries and more than one million remain displaced within South Sudan's borders. In those first few days towns were burned to the ground, including homes, schools and hospitals.
A ceasefire was signed in May, but it didn't hold and reports of new fighting soon emerged.
Torn apart by conflict and on the brink of famine, South Sudan's future hangs in the balance. And with 60 percent of the population under 18, children are among the most vulnerable in this escalating humanitarian crisis.
Not only have food shortages left hundreds of thousands of children at risk of malnutrition - children have also been subjected to horrific violence.
I know what it's like to lose your childhood to war. When I was five and conflict raged in Sudan, my family and I were amongst the lucky ones to leave for Egypt. Four years later we were granted asylum in the United Kingdom. Inspired by legendary South Sudanese basketball player Manute Bol, my siblings and I took up basketball which helped us fit in. Like Manute, I was lucky enough to turn the sport I loved into a career as a professional NBA player in the United States.
Many children in South Sudan now are not so lucky. Their lives have become a battle for survival, their childhoods ripped out from under them.
In several parts of the country children have been attacked, abducted and killed, they have witnessed atrocities and watched killings of family members. Many have been separated from their families in the chaos of attacks, arriving at camps alone and unsure if their family survived.
The education system in South Sudan already faced many challenges, but now schools too have come under attack. The start of the new term came and went in February, with almost half a million children unable to go back to school because they had fled their homes or their school was occupied by armed groups or homeless families. This is the last thing needed in a country where 75% of the population is illiterate.
To make matters worse, the rains have brought further disease and misery to South Sudan's children. Roads to remote communities are becoming impassable, hindering access for aid agencies. Meanwhile, malaria and cholera have occurred because of deteriorating living conditions. Enduring such horror has a massive psychological impact on children.
Staff from Save the Children, an aid agency working in South Sudan to protect children and families, told me they have witnessed children physically shaking or dropping to the ground when they hear loud noises, while some have become mute. Children recovering from violence need protection and support now to help them cope and avoid long-term psychological damage.
Many of those who have made it to camps for displaced people in places like Akobo near the Ethiopian border have been able to join Save the Children's child-friendly spaces, which provide safe places for children to be kids again, to play and forget about what they have lived through.
What must be done to end this horrible suffering?
All parties must honour the agreement to cease hostilities signed in May. There must be no more attacks on schools and hospitals. The violence and brutality against children has to stop. Aid workers from agencies like Save the Children must be free to deliver assistance wherever it is needed.
But most of all, funding is urgently needed to save lives and prevent further suffering in the coming months. The international community and South Sudan's leaders must step up immediately to help the children of South Sudan.
What is happening now is tragic, but it could still get a whole lot worse.
Luol Deng is an NBA basketball player who has played for the Chicago Bulls and the Cleveland Cavaliers, founder of the Luol Deng Foundation and supporter of Save the Children's child protection initiatives in South Sudan.
All images supplied for Save the Children.