Demi Lovato credits her three years of sobriety to her boyfriend Wilmer Valderrama.

The 22-year-old pop singer has been open about her struggles in the past, which included substance abuse and dealing with bipolar and eating disorders. She was able to turn her life around three years ago by going through various treatments, and Valderrama, 35, was there to support her.

On Sunday, March 15, the former Disney star posted a really sweet message on Instagram expressing her gratitude for her current flame.

The photo, which featured Lovato and Valderrama locking lips, was captioned: "I wish I could put into words how grateful I am for this man right here. But my love has grown to a level that words could never possibly express how much this man completes me... He's loved me the way I never thought I deserved to be loved and with this day marking my 3rd year sober... After sharing my ups, putting up with my downs and supporting my recovery... he still never takes credit."

She concluded, "I really wouldn't be alive today without him. I love you Wilmer."

The "Really Don't Care" songstress will celebrate her sobriety birthday with her first annual Lovato Scholarship Benefit to be held on Wednesday night, March 18, at Los Angeles' Troubadour, E! News wrote. Proceeds from ticket sales will go to The Lovato Treatment Scholarship, a charity "which funds mental health treatment for individuals with financial hardship," the news outlet explained.

Valderrama also declared his love for Lovato via social media. In an Instagram post, he said: "Today, we lay another stone together. It is now 3 years since you said: I am more important [than] any past, demon, disorder or addiction. Where you decided that YOUR life was worth living while loving yourself. And I'm sure glad you did. I knew then the woman you've become now. I am proud and honor[ed] to be front row to see the world you are about to change. I love you Demi."

Through Twitter, Lovato also thanked her fans, friends, and loved ones who have been supporting her all these years.

In a tell-all interview in 2013, Lovato revealed that she "couldn't go 30 minutes to an hour without cocaine" and would even bring it while she's out in the public, particularly in airplanes, Daily Mail reported. She went to rehab in 2010 for three months at the Timberline Knolls residential center after she allegedly punched a backup dancer named Alex Welch.

Now, the songstress regularly promotes a healthy lifestyle and she shares photos of her journey on Instagram. She also imparts inspiring messages through social media. The most recent one was of her and Valderrama working out together and a snapshot of Lovato lounging under the sun, PEOPLE noted.