'Wake-Up Call!' Selena Gomez ‘Freaking Out’ Over Friend Demi Lovato’s Overdose

Demi Lovato’s terrifying drug overdose has been a “huge wake-up call” for her longtime friend Selena Gomez, a source told RadarOnline.com exclusively.

“Selena is freaking out about this,” a source close to the 26-year-old “Slow Down” singer told RadarOnline.com exclusively. "She feels like it could have been her."

As RadarOnline.com previously reported, Gomez was spotted drinking in New York recently following her ex Justin Bieber's quickie engagement to Hailey Baldwin just a few months after they split. The singer went to rehab twice: once in 2014, and a second time two years later. She also underwent a kidney transplant last year in her longtime battle with Lupus.

Gomez is angry with the "Sorry Not Sorry" singer's friends, who partied with her the night before the overdose at Saddle Ranch bar in Hollywood until the wee hours of the morning.

“She is blaming Demi’s friends for the overdose, as well as her relapse,” the source told RadarOnline.com.

The source also said Gomez, who is now in Los Angeles after an extended stay in New York City, visited Lovato in the hospital this week. (RadarOnline.com previously reported that Lovato's ex-boyfriend Wilmer Valderrama and close pal Dani Vitale also were by her side in the medical facility.)

While Gomez has not spoken out publicly about Lovato's overdose, her mother Mandy Teefey — who recently rekindled her broken relationship with her daughter — shared a photo on Instagram of the two former Disney stars as teens.

Teefey wrote: “@ddlovato we love you. The world is a better place because of these infectious smiles. My heart hurts.”

As RadarOnline.com first reported, Lovato is heading to rehab after her imminent release from the hospital.