By Chuck Hadad

CNN

ORLANDO (CNN) -- Christine Leinonen's grief lies just beneath the surface, her tears never far away, her heartache so acute that it's palpable in her presence.

"I feel like the last day of my innocence was June 11th," said Leinonen. "June 12, everything changed ... it went from just being simple and quiet to being horrific."

Leinonen's son Christopher was murdered, along with 48 others -- including his boyfriend, Juan Guerrero -- at Orlando's Pulse Nightclub on June 12, 2016.

Christine Leinonen spoke to Anderson Cooper for an upcoming CNN Special Report titled "The Pulse of Orlando: Terror at the Nightclub." They first met just days after the tragedy when, despite her profound grief, she felt it vital to speak to CNN about her son.

"The love is going to usurp the hate," said Leinonen, adding, "Christopher was Orlando's child. Even though I gave birth to him, Orlando is now his adopted mother because she made Christopher feel the love and acceptance."

In the year since the Pulse terror attack, Leinonen has turned her grief into action and now champions two separate causes -- she promotes gay/straight alliances with an organization founded in her son's honor called The Dru Project, and she advocates for stricter gun laws.

"(My son's) voice was silenced ... I'm obligated to be his voice for him," said Leinonen. "Just because he died, my love and devotion didn't stop for him. It's just that instead of watching it from the quiet life, now I'm compelled and obligated to love and be devoted to him in the public life."

'I have to forgive'

Angel Colon is the definition of "survivor." He was shot six times, suffered a broken femur from being trampled by a panicked crowd, and has undergone four operations to regain the ability to walk. While he still battles to recover physically, he decided the only way to move forward mentally was to forgive the man responsible for the attack.

"It's something I fought with myself for many of those nights where everyone was sleeping and I was the only one up in the hospital," said Colon. "I prayed every night to God. And I made up my mind and I said, 'I have to forgive. I won't forget what happened but I will forgive.'"

Like Leinonen, Colon has become an activist in the wake of Pulse -- his cause is fighting for LGBT rights. Just before speaking at a recent AIDS awareness walk in Orlando, he admitted that being in front of a crowd makes him feel like a target. However, he did not want fear to overcome him. "I'm trying not to let that stop me from doing better for this community," he said.

Brothers in tragedy

Colon would have likely been victim number 50 had it not been for Corp. Omar Delgado, one of the first police officers on the scene. By the time he pushed his way through fleeing survivors to get inside Pulse, the shooter was holed up in a bathroom.

As Delgado's eyes adjusted to the darkness, the full magnitude of the carnage came into focus.

"I start scanning the floor. Nothing but bodies. And I noticed a couple people started to move and that's when I went into action," said Delgado.

One of those people was Angel Colon, who was quickly dragged outside to safety by Delgado and taken to the hospital.

The two reunited days after the attack and, in the year since, have remained so close, they call each other brothers.

"He'll send me (a text message) 'I love you' and I always respond back 'I love you more,'' said Delgado.

Their mutual support has helped Delgado battle his own mental injuries as a result of the tragedy. He has been diagnosed with depression and PTSD.

"There are a lot of first responders out there that do not get therapy," said Delgado. "Once you come out publicly and say you need help ... it kind of makes you look weak. But you know what? I'd rather look weak than deal with it because dealing with it is horrible."

'There's nothing proud about being a survivor'

Jeannette McCoy never leaves the house without her gun. She too lived through the horrors of June 12, 2016, and, while she escaped physically unscathed, she bears the scars of trauma and survivor's guilt.

"It's hard to say that I am here because of God because, I'm sorry, I don't believe that God would take those people the way that they were taken," said McCoy. "There's nothing proud about being a survivor. Not for me."

While the personal trainer and professional body builder surpassed many milestones in the last year -- from returning to her beloved gym months after the attack, to sleeping with the lights off for the first time -- she never feels safe anymore.

McCoy does, however, feel some sense of protection with her gun perennially strapped to her chest. "I never want to be in a situation where someone has a gun and I don't because I would feel too helpless," she said. "That night ... I was helpless."

'We will not let hate win'

Barbara Poma opened Pulse nightclub in honor of her brother, who died of complications from AIDS. She was out of town when the attack happened and first heard of it from her manager on the scene screaming into the phone.

"It was a nightmare," said Poma. "It was so sad to see something that was so happy become so awful."

Her mission now is to turn Pulse into a permanent memorial for the 49 people murdered on June 12. She helped found the onePULSE Foundation, a charity to support the memorial, as well as help the families of the victims.

Poma, along with grieving family members, survivors, first responders, and others touched most deeply by the tragedy, is determined to forge the legacy of Pulse from tragedy into triumph.

"We will not let hate win. We will heal together. Pulse will always continue to be the heartbeat of Orlando."