Demi Lovato insists she "really wouldn't be alive" without boyfriend Wilmer Valderrama.

Currently celebrating her third year of sobriety, the 22-year-old recently posted on photo of herself and Valderrama on social media, where she also raved: "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 can could never possibly express how much this man completes me. He's loved me the way I never thought I deserved to be loved," People reports. 

The former "X Factor" judge later added: "... 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 and I want the world to know how incredible his soul is. I really wouldn't be alive today without him. I love you Wilmer."

Lovato also took the time on social media to thank family members and fans for their love and support over the years.

"I'm still catching up to texts and congrats tweets," she posted. "Thank everyone who has supported my journey. I never knew sobriety was possible for me."

In another post she added: "But with the love and support I've been given from my friends, fans, and family... I now celebrate my 3rd birthday. Thank you to everyone."

In recent times, Lovato has also publicly struggled with eating disorders, prompting her to become and advocate for healthy living and eating through many of her posts. In a recent photo, she displayed her Valderrama working out and later sunbathing together.

The happy couple have been publicly dating as far back as early 2014 and on his birthday in January last year Lovato saluted him as being "incredible."