L.J. Williamson thought she was being honored at a pep rally last Friday for her work with a local program that helps kids in need at Christmas.

Instead, the mom of two and retired Atlanta Police Department officer received the surprise of a lifetime.

Williamson's oldest son, U.S. Army Spc. Shakir Aquil, ran into the pep rally at Therrell High School and surprised his mom, a school resource officer, after a two-year deployment in South Korea.

The tears quickly fell from Williamson, who said her honest first thought was, "Why did he do this to me?"

"I don't like showing emotion in front of people, and I try my best not to," Williamson told "Good Morning America." "As a police officer you're expected to be stern, and I thought why did he do this in front of all these people?"

Williamson's shock quickly turned to pure joy as she got to hug her 22-year-old son for the first time since December 2017, when he returned home for his grandfather's death.

"I'm so happy," Williamson said. "I'm still floating."

Aquil, a chef in the U.S. Army, left for basic training in Oklahoma right after high school. From there he went to Virginia for more training and then to Seoul, South Korea.

"I cried for probably about a month," Williamson said of when Aquil was first deployed. "This baby that I had when I was a baby -- I was just 18 when I had him -- we kind of grew up together and I felt like a part of me was displaced with him being so far away."

Aquil describes his mom as his "best friend" and said he also struggled with being so far away.

"Honestly, it was pretty heartbreaking," he said. "I'd see other people with their parents, even in movies, and it was a very sensitive part."

"She made everything amazing in my life," he said of Williamson. "She tries her best."

When Aquil found out he would have time off before moving to his next station in Seattle, he decided to fulfill a lifelong dream and give his family a homecoming surprise.

"I've always wanted to do it, even since high school when I was looking into going into the Army and always watched the coming-home videos," Aquil said. "I've been planning this for years."

Aquil told his mom he was coming home to Atlanta on Jan. 22 and then coordinated with Therrell High School officials and one of his mom's close friends, a fellow school resource officer, to make the surprise happen a few days early.

After a 19-hour journey from Seoul to Atlanta, Aquil first stopped at his 12-year-old brother's school and surprised him in class. Then the two brothers went to their grandmother's house and surprised her before making their way to the high school.

The school first played a video of Aquil congratulating his mom on her recognition before he ran out behind the boys' basketball team.

Aquil said he got nervous before the surprise, but the only second thoughts he had about doing it were because he wanted to see his mom even sooner.

"I didn't even want to wait for the pep rally," he said. "I just wanted to see my mom."

The surprise exceeded his expectations, Aquil said, adding, "It took me by surprise almost more than the surprise for her."

The family is now "dancing, singing, cooking and hanging out together," according to Williamson, until Aquil has to report to Seattle in early February.