Christina Grimmie’s Murder Sent Selena Gomez ‘Spiraling’ Into Drug Abuse

RadarOnline.com can exclusively reveal that Selena Gomez was forced to check into rehab after it became clear she was still reeling from the tragic murder of her close friend Christina Grimmie.

A source close to Gomez said the singer "began spiraling" after Grimmie was killed by a crazed fan in Orlando on June 10 and she was doing what she could to numb herself.

“I don't really understand how this really happened,” Gomez told fans in tears during a concert shortly after 22-year-old Grimmie’s death.

"Selena wasn't the same after that," the insider told RadarOnline.com. “She was definitely depressed — it was obvious."

As RadarOnline.com exclusively reported, Gomez put her Revival Tour, which still had dozens of concert dates left, on hold Tuesday, after a desperate intervention from family members concerned about her escalating drug use.

According to the source, Gomez, 24, was taking a cocktail of "Lunesta, Ambien, Klonopin and Xanax. Not all at once. And more 'recreational' than any one thing specifically."

While Gomez’s rep did not respond to RadarOnline.com’s request for comment,

this isn’t her first time in rehab.

Gomez had a hush-hush stay at an Arizona facility in January 2014 for what an insider said was Gomez’s abuse of Xanax, Ambien, marijuana, among other substances.