A Long Island mother said in an emotional social media post that her son was bullied so badly he has spent the last five weeks in a hospital being treated for an eating disorder and depression.

In the Facebook post that has been shared more than 1,000 times since Wednesday, Deidre O'Brien described merciless bullying her son Liam faced while at Garden City Middle School and on the soccer field during seventh and eighth grades -- and that the school's investigation into their son's case was this week deemed "unfounded."

"My beautiful son Liam turned 13 years old on September 8," she said. "He should be in school with his friends getting excited about high school and playing soccer, but he is not. He is at a medical center in Princeton NJ being treated for depression and an eating disorder."

On Friday, she told News 4: "He was bullied all year he said he was told that he sucked st soccer, didn’t deserve to make the team. He said, 'Every day mom, every day.' It just broke him."

In the post, O'Brein described more than a year of bullying that began last fall once he made the seventh-grade soccer team. She said her son loved to eat and play soccer at the time, but toward winter break things started to change. She wrote that he gave her his iPhone -- describing it as "too much drama" -- and opting to spend time with her and his father, Keith O'Brien, instead of friends.

She said toward the end of the school year, someone punched him on the way to the school bus home. That summer, he opted to spend more time with his father training horses and even though he made the soccer team again, his mother wrote that he didn't pick up a ball all summer.

And he started losing weight. O'Brien wrote that Liam's father noticed that he wasn't eating when he was with him, and he was admitted to a children's hospital when doctors found out he lost 10 pounds in a month. Once the school year started, he lost another five pounds.

"I sobbed looking at him because he was just bones," Diedre O'Brien told News 4. "I said to Keith, 'He’s going to die.'"

She said they took him back to the hospital after his birthday on Sept. 8, when he came home from school with bruises on his face. He didn't eat at his birthday dinner and didn't go back to school the following Monday.

"We sat at the kitchen table and we cried and I said please tell me what happened," she wrote. "He finally couldn’t hold it in anymore. He told me he was bullied terribly in 7th grade. It started when he made the soccer team. 2 kids told him he sucked and shouldn’t have made the team. There were unnecessary pushes and kicks. He was told he was weird, he was fat, his freckles were weird, his eyebrows were weird. They used horrible language and called him nasty words."

She added, "I asked him how often it happened. He looked at me crying and said, 'Everyday Mom.'"

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Diedre O'Brien said that they reported the bullying to the school, and that the school's investigation was closed on Wednesday and deemed "unfounded."

"I was told Liam’s perception may have been different from reality," she wrote in the post. "They just couldn’t find evidence that this happened. I have a picture of a bruise on his face, they said staff said he didn’t exhibit behavior that would suggest something just happened to him."

Keith O'Brien later told News 4, "It hurts, it’s almost like they are saying we don’t believe you or perhaps the perception of what your child felt wasn’t really real."

The school district told News 4 it couldn't comment directly on Liam's case because of confidentiality laws.

"We want to be on top of this, we don’t want to lose any child. Even one case is one too many,” said superintendent Alan Groveman.

The O'Briens, meanwhile, is calling on families and their students to take a stand on bullying -- and not to simply make empty gestures on the upcoming Unity Day, the Oct. 25 holiday where people don orange in solidarity with bullying victims.

"I think we can do more than an orange shirt," she wrote. "The school has closed their investigation, but this is not over. I want Liam’s story to be heard."

If you are in crisis, call the National Suicide Prevention Lifeline at 800-273-8255 or reach out to the Crisis Text Line by texting ‘Home’ to 741741.