How Kim Zolciak-Biermann's Stroke and Surgery Are Taking a Toll on Her Kids

The former Dancing with the Stars contestant says her health crisis has been hard on her little ones

Photo: Dimitrios Kambouris/Bravo/NBCU Photo Bank

When Kim Zolciak-Biermann was in the midst of having a stroke on Sept. 23, the first thing that came to mind was her children.

“I thought, ‘If I pass out in front of my kids, they’re just going to die!’ ” the former Dancing with the Stars contestant tells PEOPLE in this week’s issue.

At home at the time, she’d just leaned down to hug her 4-year-old son KJ when she felt a strong tingling sensation throughout her body and became very dizzy.

“I kept telling myself ‘Kim, you better keep yourself together.’ “

The mother of six tried her hardest to put on a brave face, even when doctors informed her and husband Kroy that they’d found a hole in her heart that required urgent surgery.

RELATED VIDEO: The Story Behind the Story of Kim Zolciak-Biermann’s Conversation with PEOPLE

The traumatic event has taken a toll on her kids, Zolciak-Biermann says.

“It’s been hard on my kids, but KJ has taken it the worst,” she says of her eldest son, who witnessed the whole ordeal. “I was trying to tell my nanny to take him away during the the whole thing, but she was too worried about me.”

Since that day, “He has been kind of difficult to handle,” she says, “and it finally hit me a few days ago. He knew I was going to have surgery, and he kept asking every night, ‘Mommy is it tomorrow?’ It broke my heart.”

Now, with heart surgery successfully behind her, she says KJ is feeling much better.

“He’s a totally different baby now that it’s over,” says Zolciak-Biermann, who’s recovering and eager for the day she’s able to pick up her son and his younger siblings again.

“He came in right after the surgery and spent the night with me,” she says. “He actually asked me this morning, ‘No more hospitals, right Mommy?’ And I was like, ‘No more, honey.’ ”

For more on Kim Zolciak-Biermann’s health scare and recovery, pick up this week’s issue of PEOPLE, on newsstands Friday

The season finale of Don’t Be Tardy airs Thursday at 10 p.m. ET on Bravo.