Opening up. Teen Mom OG’s Amber Portwood is aware of her mistakes — and is ready to move forward. In the new issue of Us Weekly, the reality star, 29, opens up exclusively about what happened between her and Andrew Glennon and the aftermath.

“I got into a really, really dark period for a couple of months,” she tells Us. “I lost about 35 pounds in less than three months. My hair was falling out. When I say I went into shock, I literally, my body went in shock. I didn’t sleep for almost two weeks. I had to get out of that state of mind.”

Portwood was arrested in July 2019 for domestic battery against ex-boyfriend Glennon, 35. According to police, the pair were in an argument and she hit her boyfriend “while he was holding” their son, James, who is now 22 months old. Portwood also shares daughter Leah, 11, with ex-boyfriend Gary Shirley.

“It was definitely a deep depression that I went through,” she continues. “Through prison and everything I’ve been through, it was one of the worst times of my life, and when you go through something like that, you have to learn from your mistakes.”

In an exclusive first look at the season, the former 16 and Pregnant star gets emotional talking to Shirley, 33, about how angry she is with herself.

“The No. 1 regret that I have is that I did not walk out of the house that night. Now I look back and I’m so ashamed because all I keep thinking about is, ‘Amber, you should have walked out of the house,'” she reveals to her ex. “There are limits to somebody with mental health disorders. There’s only so much somebody like me can handle and people like me will understand that. … I just have a lot of guilt of not being aware of myself more than I should have.”

Later in the clip, the producers also call Glennon, 35, and tell him they want to share both sides of the story.

“It’s giving me anxiety, to be honest with you,” he says in the clip above. “It’s hard to go to sleep. It’s a total mess. It’s completely spiraled out of control, I feel like, and it’s really frustrating.”

For more from Portwood, pick up the new issue of Us Weekly, on stands Wednesday, March 11.

Teen Mom OG returns to MTV Tuesday, March 17, at 8 p.m. ET.

With reporting by Brody Brown