"So grateful. It's been quite the journey. So many ups and downs. So many times I wanted to relapse but sat on my hands and begged God to relieve the obsession," the 24-year-old singer wrote. "I'm so proud of myself but I couldn't have done it without my higher power (God), my family, friends, and everyone else who supported me."
"Feeling humbled and joyful today," she added. "Thank you guys for sticking by my side and believing in me."
Lovato opened up about her "sober birthday" milestone to ET's Lauren Zima at the 2017 Kids' Choice Awards over the weekend, admitting, "It feels amazing."
"All I've been doing is focusing on bettering myself. It's been quite the journey, but it's well worth it," she shared. "Surrendering is the most important thing whenever you're trying to battle your demons ... You have to admit that you have a problem first, and then you can overcome them."