This Mom Lost 208 Lbs. for Her Son: 'I Didn't Want to Be the Reason Why He Lost Both of His Parents'

"I feel like I prolonged my life to be here for my son and everyone else that needs me," says Tiesha Robinson, who lost half her size

Tiesha Robinson found the motivation to get healthy in her 15-year-old son DeVontay.

The mom and accountant, 35, had tried "almost every diet" after years of struggling with her weight. Robinson remembers being overweight by age 5, and by the time she finished high school, she was "probably more than 300 lbs."

"I tried just eating fruits and vegetables, which didn't last for more than a few days, and eating only proteins," she tells PEOPLE for the Half Their Size issue. "But my mind also wasn't there to be able to commit to anything."

After high school, Robinson continued to gain, before and after her pregnancy with DeVontay, and hit her highest weight of 416 lbs. in 2017, after her aunt passed away. At that point, "I was basically addicted to sweets," she says, and "barely drank water."

At every doctor's visit, Robinson would "pray that I wouldn't have any issues," but that year, she learned she was pre-diabetic.

"It kind of hurt my feelings when she prescribed me the medicine and she said, 'It'll help you lose weight,' " Robinson says of learning she was prediabetic. And that turned out to be motivating. "I was like, 'If I can do this in a healthy way, I'd rather try to do it naturally,' because actually, the pills was making me put on weight, rather than doing what it was supposed to."

For more Half Their Size stories, pick up a copy of PEOPLE, on newsstands Friday

She started doing WW, but her mind wasn't in it quite yet. Then, in Oct. 2018, her son's father died.

"It made me realize that my son only has one parent," she says. "I didn't want to be the reason why he lost both his parents, if I could help it. I didn't want to leave my son prematurely because of the unhealthy decisions I was making."

That pushed Robinson to fully commit to WW and "show up for myself the same way I would for everyone else." She started tracking her WW points to figure out how to eat meals that would keep her full for longer, lowered her sweets intake and swapped sodas for water, and quickly started to lose weight.

"I noticed that when I wanted sweets but had more protein instead, I felt full for longer and I felt less sluggish," she says. "I had more energy and I just felt a lot healthier."

Erin Bowman

Robinson also started doing Zumba and dance workouts at home, where she didn't feel intimidated by people at the gym. "I don't have no excuse if I'm in my own house," she says, laughing.

Robinson hoped to get down to around 200 lbs., but felt like it was an "intimidating" number — "so I just started taking it 5 or 10 lbs. at a time, and I celebrated every milestone, like getting to 375, and 350, and being under 300."

And after about two years, Robinson lost half her size, and is now down to 208 lbs.

"But it's not just about the scale," she says. "It's a whole shift, and I'm loving it. My confidence is higher, I'm no longer pre-diabetic and I don't have any health issues. It's a blessing."

Plus, Robinson is able to be there for her son.

"I know you can't control everything, but if there's something that I could prevent by eating healthy, then I'm glad I'm able to do it," she says. "I feel like I prolonged my life to be here for my son and everyone else that needs me."