Photo: Alberto E. Rodriguez/Getty Images

de-la-garza-lovato-1-2000

Demi Lovato’syounger sister Madison De La Garzabroke her silence about thestar’s relapse and overdoseon a very special day: the singer’s 26th birthday.

“Today could have been one of the worst days of my life, but instead i get to spend it thanking God, the incredible doctors, demi’s team, and everyone across the world who offered their support — without all of these people i wouldn’t have my big sister anymore,” the 16-year-old actress wrote Monday in a heartfelt tribute to Lovato.

“I’ve been thinking about how i wish that everyone could see the silly little things that she does, like how her nostrils move when she says certain words and when she brushes my hair behind my ear when i’m trying to sleep, because those are the things i’m so thankful for today,” she continued on Instagram while sharing a childhood photo of herself and Lovato.

“They seem so small, but those little things make up my sister — not a singer, not a celebrity, and definitely not what she’s been described as in the media — she’s a daughter, a friend, and my big sister… and i am so, so thankful that i can tell her happy birthday,” De La Garza concluded.

Sources previously told PEOPLE De La Garza rushed to her big sister’s side afterher shocking overdoselast month and was one of her biggest supports through her latest setback.

“That was a very heartbreaking time in my life because we basically sat down with Demi and said to her, as much as it hurt me, ‘You have to get serious about getting help and getting sober because you have a little sister, and I can’t allow her to be around you if this is how it’s going to be,’” De La Garza previously told PEOPLE.

“That was the defining moment for her. That’s when she took her phone, smashed it and put it in a glass of water, as a sign that she was ready to commit,” Dianna wrote in her 2018 memoirFalling with Wings.

“Thank you for all your love and prayers… I am truly blessed. #thankful #happybirthdaydemi,” Dianna wrote on Twitter and Instagram Monday, sharing her daughter’s post.

RELATED VIDEO:Demi LovatoBreaks Silence After Overdose and Hospitalization: ‘I Will Keep Fighting’

After beingreleased from the hospitalon Aug. 4, Lovato has beenundergoing in-patient treatmentandthanked her fanson social media for their support in an emotional statement.

“She’s in the midst of recovery,” a source close to Lovato previously told PEOPLE. “It’s going to be a long road, and Demi knows that. Emotionally, it hasn’t been easy, but she’s doing okay.”

source: people.com