Demi Lovato posted a heartfelt tribute to her friend, Thomas, who died after his struggles with addiction.

The "Sorry Not Sorry" singer took to her Instagram Stories on Wednesday (October 9) to reveal how "devastated" and "crushed" she felt as she mourned her close pal, who passed away from a suspected overdose.

"Devastated. Please hold your loved ones tight," Lovato wrote alongside a black-and-white photo of Thomas. "Tell them they are special and that you love them. Make sure they know it. RIP to my boo."

"Addiction is no joke," she added in a second Story. "Heaven gained this beautiful angel last night because of that terrible disease. I'm crushed and will always miss you @sirtruss. If you or someone you know is struggling please know it's okay to ask for help."

The 27-year-old pop star allegedly suffered from a drug overdose last summer that nearly took her life so she knows firsthand how difficult it is to struggle with addiction. After being hospitalized for weeks and then checking herself into rehab, Lovato opened up about her struggles in a candid Instagram post.

“I have always been transparent about my journey with addiction,” she wrote at the time. “What I’ve learned is that this illness is not something that disappears or fades with time. It is something I must continue to overcome and have not done yet. I want to thank God for keeping me alive and well. To my fans, I am forever grateful for all of your love and support throughout this past week and beyond. Your positive thoughts and prayers have helped me navigate through this difficult time.”

Since then, Lovato has continued to focus on her mental and physical health, which includes returning to the studio to record a new album, hiring manager Scooter Braun and spending time with her friends and family. She also starting watching The Bachelorette, which led to her rumored romance with contestant Mike Johnson.

Celebrities Who Don't Drink