Zach, a 22-year-old military cop who married a woman, describes looking in the mirror and seeing someone else completely. "I am not a man, so I don't want to see a man when I look in the mirror," Zach explains. "I love having long hair, I love having my nails done, I love makeup, clothes and shoes and everything about being a woman. That's when I'm the happiest."

In the video above from Fridays episode of Dr. Phil, Zach, who now goes by Steph, discusses realizing that she was transgender.

"Cross-dressing is something that I've done all my life. It started around the age of 7. I remember I put on a dress and heels and it felt amazing," says Steph. "I remember feeling liberated and girly when I dressed in women's clothes."

Former Navy Seal Explains Growing Up Transgender

Steph married her high school sweetheart three years ago. "I didn't realize I was transgender when I first got married," she explains. "I wasn't sure what was going on with me."

After soul-searching and research, she concluded that she was transgender. "I identify as a woman mentally and sexually," says Zach. "At this stage, I feel like I'm more physically attracted to men."

But it's been very difficult for Steph's family to accept her transition, especially for her dad, Gary (who is biologically Steph's uncle but raised her since she was 2 days old and considers himself Steph's father).

Watch as Gary describes his reaction when he learned that Zach wanted to become a woman. This episode of Dr. Phil airs Friday. Watch more here.