It was the dancing competition show's famous "Most Memorable Year" week, and in a pre-recorded package played before her performance, the 34-year-old Fuller House actress opened up to her pro partner, Keo Motsepe, about the challenges she's faced.
"My most memorable year has been this past year of my life," Sweetin said, opening up to Motsepe. "Getting to step back in and find my dreams and the thing that I love again."
Sweetin got very candid about her struggle with substance abuse and how she fell into a "dark place" after Full House wrapped in 1995, when she was only 13 years old.
"It was a huge shift in my life. Everything I had known from the time I was five years old suddenly ended and it was like saying goodbye to a family I had loved very, very much," Sweetin explained. "At such a young age it really was a huge loss for me [and] I didn't know how to grieve."
"Drugs and alcohol just sort of numbed everything. I was doing cocaine and ecstasy and alcohol and all of that," she recounted. "The darkest moments for me weren't necessarily winding up in the hospital or anything like that. It was those quiet moments alone when I just hated the person I had become."
Comedian Bob Saget, who began working with Sweetin on the original Full House when she was just 5 years old, praised her for being an amazing mother to her two daughters, 7-year-old Zoie and 5-year-old Beatrix.
"She's a great mom because she's been through so much, and with that comes honesty, and the more honest you are with your kids the more you can be real with them," an emotional Saget shared. "I think her biggest accomplishment is that she's just incredibly real. And that's one of the things I love the most about her."
Speaking with Motsepe about her healthy progress, Sweetin shared an emotional story about her mom. "I remember my mom saying that when I was little, I had this light that shined really big, and that she had watched my light become very dark," Sweetin recalled. "And I just remember my mom saying to me, 'You're light shines again.' So, through doing this dance, I get to shine again."
"I dimmed my light for a long time, and I don't feel I have to do that anymore," she added.
During her emotionally charged Foxtrot -- set to a live performance of "Rise Up" by Andra Day -- Sweetin made sure to shine, stepping out of the darkness and back into the light with a powerful routine that left her beaming.
The dance also left the judges impressed as they heaped praise on the star. Bruno Tonioli said it was Sweetin's "best performance to date," while Carrie Ann Inaba called it "the most inspiring performance of the night." Even Len Goodman said they did "a wonderful job" of portraying the emotion through their movement.
With an 8 from Inaba, a 7 from Goodman and an 8 from Tonioli, Sweetin and Motsepe earned a score of 23, which is their highest score of the season so far.