(CNN) -- Tyrone Garrett's father wasn't around while he was growing up. So when Garrett's girlfriend, Whitney Hammond, told him she was pregnant, he knew he had to make a change.
Garrett, then 26, weighed 335 pounds. Like many members of his family, he had high blood pressure, but he refused to take medication. One time at work, his heart started beating so fast he could see it moving up and down through his shirt. Hammond rushed him to the doctor, who warned that he was dangerously close to having a heart attack.
"It was the scariest thing in my life," Garrett says.
That experience, combined with the arrival of baby London, on March 5, 2011, finally inspired him to get fit.
"Being around for my only child was something I made a priority," Garrett says, his voice warming as he talks about his daughter. "She's awesome."
Garrett bought a set of workout clothes and a pair of running shoes and headed to the gym. "I remember it like it was yesterday," the Manchester, Connecticut, resident says. "I was nervous in front of everybody because I was so obese."
His first workout included a little bit of everything. Without a trainer, Garrett followed his instincts. His only rule in the beginning was to sweat. A lot.
After a while, he turned to the Internet to learn more about nutrition. He started watching what he ate and counting calories. He stayed away from foods that were high in sodium to lower his blood pressure and avoided sweets.
In the first month, he dropped 50 pounds. Over the next year and a half, he lost 130 pounds. He has shed about 10 more pounds since then.
Garrett wakes up every morning at 3 or 4. He hits the gym, doing at least 45 minutes of cardio and two hours of weight training. Sometimes he swims laps. Other times he sits in the sauna to "sweat out the toxins." He brings light snacks such as bananas and protein bars to keep up his energy during the long workout.
After three or four hours, he heads to work. He has a full-time job and two part-time ones to support Hammond and London.
"They are my drive and my support system on this (w)eight loss journey," he wrote on CNN's iReport.com.
After work is daddy-daughter time. Occasionally, if there's time after London is in bed, Garrett heads to the gym again.
Hammond fully supports her fiance's near-obsessive workout schedule. "(He) just wants to maintain what he worked so hard for," she wrote in an e-mail. "And if I need him, no matter what machine he's doing, he will drop it and run to his family."
The couple met in high school and have been together for almost 13 years. Their wedding is set for June 15.
"His weight loss has changed his whole outlook on life," Hammond says. "He loves his new lifestyle and only wants to go up from here."
Garrett's changes have crept into Hammond's life as well. She's altered her eating habits and takes her daughter on daily walks to stay active. She's looking forward to a long life with her future husband.
Garrett doesn't allow himself full cheat days -- "the fear of messing up and going backward is still there" -- but he does splurge once in a while on some extra chicken wings or a bigger meal than usual.
There are days when his legs and arms hurt and his bones ache from all the exercise, but he reminds himself that no one else can do the work for him. He's at 194 pounds and wants to reach 180. That said, any extra weight loss at this point is simply a bonus to being healthy.
"As long as I can wake up every morning and breathe in and out, I'm cool with everything else," Garrett says.
He loves to go outside and play with his daughter without breathing heavily or sweating excessively. He likes not having to worry about going to the doctor or taking medications. He's thrilled that others have been inspired by his story; a co-worker lost 80 pounds and several family members have lost more than 50.
"It's coming from me," he says, almost in disbelief. "You never would have thought I would be a lean guy. Sometimes I have to pinch myself to make sure it's real."