Katy is still ‘devastated’ after being dumped by Russell Brandand friends like Rihanna are worried about her!

Katy Perry is headed to Vegas for the grand opening of 1Oak on Jan. 27 but don’t think she’s going to Sin City just to party. HollywoodLife.com spoke to a friend very close to the singer who tells us she’s “doing her best to not back out of her commitments” even though she’s upset that Russell Brand filed for divorce.

“Katy’s friends are doing everything they can to help keep her happy and just be there to listen to her,” our source says. “Rihanna has been unbelievable and checks up on her every day and even invited her on a trip. Katy even asked Rihanna to meet her in Vegas and be there with her.”

Katy is headed to Vegas to attend the GiveLove charity with her buddy Markus Molinari for the celeb-filled charity party. We’re happy that Katy is attending since she backed out of the People’s Choice Awards on Jan. 11 at the last minute.

“Katy has really lost her appetite though,” the source continues. “She is doing her best to remain upbeat while at work but she is deeply hurt.”

Katy just got back from being on tour in Indonesia and we were told she was happy to “get away from the drama.”

— Chloe Melas

More Katy Perry:

1. Katy Perry Stops Following Russell Brand On Twitter
2. Katy Perry’s False Lash Collection Revealed
3. Katy Perry Terrified Russell Brand Will Expose Their Marriage Secrets