Anna Duggar is going to let her emotions spill over in the next Jill & Jessa: Counting On special.

During the next episode Sunday, December 20 at 8PM ET/PT on TLC -- which stars Josh's sisters Jill Duggar and Jessa Duggar -- Anna will open up about her husband Josh Duggar's mistakes, lies and secret life.

News Josh had molested a handful of girls, including Jill and Jessa, first surfaced in May. He then confessed in August to cheating on Anna, the mother of his four children, and developing an addiction to pornography.

Anna, 27, said Josh's confession "was definitely a hard thing" to handle, as shown in a preview clip obtained by People.

"I think it is such a betrayal for a spouse to go through what we're walking through," she continued, trying to hold back her tears.

Just last month, People reported porn star Danica Dillon filed a lawsuit against Josh because he had "assaulted her to the point of causing her physical and emotional injuries" during alleged sexual encounters.

"Not only was it a betrayal against me, but it was also a betrayal against those that call themselves Christian because here we were as a Christian couple," she said. "Everyone was able to see us get married and to vow before God to be loyal to each other, and that loyalty was broken. And so, for my heart, it was just broken."

Josh, 27, is currently seeking treatment in a faith-based rehab center. Anna called him "my first love. He's my one and only."

"I knew if I went off of what I was feeling, I would turn a mess into a disaster," Anna said in the video clip.

"In the stun and in the shock of everything, I was just praying, 'God, help me to respond to all of this.' I didn't know what to do. I knew we needed help, and I was just praying God would give the wisdom and the help that we needed to take the next step."

Josh's younger sister Jinger, 21, said Anna is "amazing" and displays "unconditional love."

"She's walking through this better than any one of us could have ever imagined," Jinger noted.