In 2004, Dan Nevins was deployed to Iraq with the U.S. Army. After nearly a year of fighting overseas, Dan's life nearly ended in tragedy. He became a double amputee and life as he knew it changed forever. Then, he found a new source of strength and purpose.

On November 10, 2004, Nevins and his team were driving in Balad, Iraq, when their vehicle hit an IED. "It was pitch black, around 4 in the morning," Nevins told CBS News. "I remember hearing and feeling the truck basically disintegrate around my body."

Nevins was conscious after the explosion and started feeling parts of his body to make sure each was OK. When he felt his legs, he knew something serious happened. "I felt the unmistakable blood spirt with every beat of my heart... I was losing what seemed like all of my blood in this miserable place on the planet," he said. "I was praying."

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Lying on the ground, waiting for help, Nevins thought about his daughter, who was 10 years old at the time. "I had this visualization of my daughter, all grown up and dressed in white and walking down the aisle without her dad. That was the thing — I just shot up." This vision gave Nevins the willpower to hang on. A medic soon arrived and Nevins was airlifted to a hospital, where he underwent surgery.

Nevins ultimately received over 30 surgeries and lost one leg before returning home to the U.S. He had complications with his remaining leg, and that was ultimately amputated, too. He suffered immense pain, but was grateful to be alive.

After the Army, he went back to his job in pharmaceutical sales, but felt unfulfilled. He started working with the Wounded Warrior Project and says that's when he fell in love with helping veterans.

Dan Nevins - Yoga Warrior Yoga is just one of the many ways to help veterans nurture a sound body and mind. On this International Day of Yoga, Wounded Warrior and yoga instructor Dan Nevins talks about his own experiences with yoga, and how it can help other veterans. Learn more about how you can get involved with WWP's Physical Health & Wellness program at http://bit.ly/P_HandW. #InternationalYogaDay Posted by Wounded Warrior Project on Wednesday, June 21, 2017

Nevins said he eventually got used to being a double amputee. "I found a way to thrive physically and athletically," he said. But he realized that while the physical wounds of war had healed, "it was the invisible wounds of war that went untreated."

Five years ago, Nevins had his final surgery — number 36, he said. "This was different than all the other ones," Nevins told CBS News. In the past, he received surgery at Walter Reed Medical Center and then recovered with the other veterans there. This time, he had to take off of work to travel to Walter Reed and returned home immediately afterwards to recover alone.

"In those eight weeks alone, I'm dealing with the physical pain from the surgery and I'm also just alone," Nevins said. It was hard for him being unable to take care of his daughters because he couldn't move around his house. "I was completely isolated. Alone with my thoughts," he said.

Nevins said he struggled mentally during this time. He knew the grim statistic: 22 veterans a day took their own life, according to the VA. But he didn't originally understand how dark life could get after deployment. "In those eight weeks, I got it," he said. Nevins said he didn't want to end his life, but knew he need was going into a darker and darker place. He called a friend for help.

"She said, 'Dan, you need some yoga in your life,'" he recounted. "I said, 'That's the dumbest thing I ever heard.'" Nevins said he was originally angry that yoga was even suggested as a solution for his problem. Then, he reluctantly learned some more about the spiritual and physical practice.

His friend started teaching him the basics — he agreed to take three classes with her. "It was hot and it was hard and I was off balance," he said about his first yoga session. "It was painful, miserable. Plus, I'm typically naturally good at sports. But I was bad at yoga."

During his second class, Nevins though maybe taking his prosthetic legs off would make it easier. "Nobody – I mean nobody – has seen me with my legs off," Nevins said. "But I was just like, 'I'm going to figure it out.'"

"I visualized roots growing out of my legs, into the ground," Nevins said. He pushed himself to get into "warrior one" pose and said it sent a burst of energy through his body. "I was never more alive. I felt eight feet tall and more powerful than I've ever felt in my whole life," he said. That profound experience converted Nevins into a yogi.

"It's like the earth was saying, 'Dan, where have you been for the last 10 years?'" Nevins remembered.

Just a few months later, Nevins was already in yoga teacher training. He went from a skeptic to a full-time yogi, completely devoted to the practice. For the past five years he has been traveling the country as a yoga instructor and motivational speaker. He has taught everywhere from the White House lawn to Bryant Park in the heart of New York City.

On Thursday, Nevins was in San Francisco leading a three-day training session for yoga teachers on specifically how to instruct veterans and first-responders. "As far as I know, I'm the only no-legged yoga teacher on the planet," he said. He is using his personal experience and expertise to show others how teach the community he cares so deeply about.

Nevins said he originally started teaching yoga only to veterans, knowing how much they could benefit from the practice. However, he decided to expand his clientele, realizing many people can grow and heal from yoga.

"All humans live with the invisible wounds of some war," he said. "The bigger the crowd, that's just more people I get to say, 'Hey, invite a veteran to yoga, because it might just save their life.'"