A Forever Bond: Florida Man Shares What Life is Like for His 18-Year-Old Brother with Microcephaly

Nothing will ever break Daryle Koltay and Barry Wilson's brotherly bond.

Daryle, 18, was diagnosed with microcephaly, a debilitating birth defect that has been linked to the Zika virus, the day after he was born. Barry, 29, suffers from bipolar disorder and agoraphobia – making it hard to hold down a full-time job.

The half-brothers spend almost every waking second together – relying on each other for support.

"We complete each other, we each have our own strengths and weaknesses," Barry tells PEOPLE. "For instance, he can't read and write, but he has a really good memory and can calm me down. I can read, but I have trouble emotionally.

"He's my life at this point," Barry adds.

Daryle lives with Barry and their mother Lisa Koltay in their St. Petersburg, Florida, home. Daryle was diagnosed with microcephaly, the condition causing small-head size and incomplete brain development that is causing global panic, the day after he was born.

Microcephaly first made headlines when reports linked a spike in the number of babies being born with the condition in Brazil to the Zika virus that is transmitted by Aedes aegypti mosquitos. As many as 4,000 babies born with microcephaly in the South America country drew immediate attention from the Centers for Disease Control and Prevention and the World Health Organization, who designated Zika "a public health emergency of international concern."

Lisa says she believes Zika caused the microcephaly diagnosis as she remembers being bitten by mosquitoes while she was pregnant and having a rash on her feet.

Daryle cognitively functions on a first-grade level – he struggles expressing emotion, dressing himself and communicating effectively.

"My brother and I are best friends," Daryle tells PEOPLE. "I do care about him a lot."

The half-brothers have a daily routine down. They wake up in the late afternoon, go to the grocery store, make dinner (usually steak or pizza), and watch Vampire Diaries – their favorite TV show – while chatting.

"Our life is simple, but the world outside is harsh," says Barry. "People give him funny looks in public because of his small head and I have to defend him. People will make a mention or comment to him and I'm always on the lookout. Our bond goes a lot deeper than most sibling bonds."

Barry says he remembers the first time he decided he would "always protect Daryle no matter what."

"I used to play ice hockey and I would pick him up as a kid and skate around the rink," Barry says smiling. "He would laugh and laugh, he loved that. In that moment, I knew that I would always be there for him. He is so innocent, I knew it was my duty to always be his guardian."

But their outings are not always pleasant. The older brother recalls an instance last week when a group of pre-teen girls "stared and pointed at Daryle" at a local restaurant.

"They were whispering and laughing. I don't know if it hurt Daryle as much as it hurt me, because I just felt like crying," says Barry. "I felt so bad for him, but there was nothing I could do, except to spread awareness that stuff like that hurt. It breaks my heart when people are mean to my little brother."

Daryle agrees, "That was not nice of those girls. It hurts my feelings when people stare at me."

Daryle and Barry have formed on online community called "A Brother's Bond," to promote microcephaly awareness and mental health.

"The conversation on both of these conditions needs to expand," says Barry. "There's no real community for those with microcephaly and with this global rise in babies being born with it, we think it's important there is a place where people can talk about it."

The brothers have set up a Twitter and a GoFundMe account to spread awareness.

"I think we have a purpose in life now, and it's for me and Daryle to talk about microcephaly and to begin the dialogue that needs to take place," says Barry. "He's so important to me, when we're not together I feel like half of my being is gone. And I would do anything to help him and be there for him."

Daryle smiles, "I love him, too."

For much more on Barry Wilson and Daryle Koltay, pick up this week's issue of PEOPLE Magazine, on newsstands Friday