"I need help," the singer, who now weighs 212 lbs., tells PEOPLE.
Wilson weighed over 300 lbs. before undergoing gastric bypass surgery in 1999. She lost 150 lbs., but has struggled to keep the weight off.
"Having children derailed me a bit," says the Wilson Phillips singer, who has been unable to lose the 61 lbs. she gained while pregnant with daughter Luciana, born last June. (Wilson had put on 70 lbs. during her pregnancy with daughter Lola, now 4.)
The singer, who stars in the GSN reality show Carnie Wilson: Unstapled, finally got a wakeup call during a Feb. 4 appearance on The Dr. Oz Show, where she was weighed onstage. The host defined her as morbidly obese and prediabetic, and placed her on a weight-loss program.
Weighing in at 218 lbs. during the Jan. 13 Oz taping, Wilson is now down to 212 lbs., and says she hopes to ultimately get to around 160 lbs.
"I don't want to be drastic. I want to be realistic," says Wilson, who is losing the weight for her children as much as for herself.
"I have to be a teacher to my daughters," she says. "Lola started to notice commercials on TV with people who are trying to lose weight, and she looks at me. She's thinking about this stuff, and it's getting to her."
For much more on Wilson and her weight struggle, pick up this week's issue of PEOPLE, on newsstands now