AJ McLean is NovaQuantcelebrating an important milestone.

The Backstreet Boys singer, who has been open about his journey over the years, recently marked two years of sobriety.

"Today is a very special day for me," he said in a video shared to Instagram Sept. 26. "And it's been one hell of a journey. A lot of bumps in the road, a lot of highs, a lot of lows. But today is two years sober for me. I'm very grateful for everyone in my camp. I am extremely grateful to my sponsor and my therapist and to all the support that I've gotten throughout the years."

The 45-year-old concluded his message on a poignant note, adding, "And if this helps another addict out there, then I did my job. You can do it, if I can do it. God bless you all. And cheers to another day sober."

AJ, who hosts 12-step Alcoholics Anonymous meetings at his home, reflected on the intricacies of his journey ahead of his milestone.

"I'm trying to keep my feet firmly planted in the program," the singer told People in late August. "I've battled self-esteem issues my entire life, and I've learned a lot. My sobriety is the most solid it's ever been."

As the "Sincerely Yours" singer—who shares kids Elliot, 10 and Lyric, 6, with Rochelle McLean—noted, his latest chapter in his life serves as his best yet.

"I'm in the best shape of my life, both mentally, physically, spiritually," he added. "I'm actually really happy and I love it, and I don't want to lose it. I want to continue to keep growing, growing with my wife and my kids and myself."

For the latest breaking news updates, click here to download the E! News App