Sydney Hardeman, who went viral for her stunned reaction to Beyoncé‘s 2018 Coachella set, is dead … TMZ has learned.

Sydney’s mother, Jamie Hardeman, tells TMZ … Sydney died by suicide.

We’re told Sydney took her own life last Saturday. She was engaged and set to be married this upcoming April.

Sydney was a huge fan of the “Halo” hitmaker and even won an award her senior year of high school after she performed a dance medley to her songs. She went viral in 2019 when she was just 19 years old — her reaction to Beyoncé performing at Coachella was included in Bey’s Netflix documentary, “Beyonce: Homecoming” … and she quickly became a meme.

The family says Sydney played basketball from childhood and through college, and then worked as a flight instructor in Texas. They began to notice differences in her mood after her grandfather died — though her loved ones are still trying to figure out why she took her own life.

We’re told Sydney’s family tried to get her into counseling, but she canceled her appointments.

Sydney’s mom says she went to see Beyoncé at Coachella back in the day after begging her for a ticket … and she traveled from Texas to California with her brother and best friend. Sydney was the first one in the gate, ran to the main stage, and waited 12 hours at the barricade for Beyoncé’s set.

We’re told Sydney was watching ‘Homecoming’ in her dorm and screamed when she saw herself on the screen.

Sydney’s mom has a moving message for Beyoncé fans … “You guys are young, and you are excited, you guys haven’t gotten to the good part. Lean on your village, Sydney had a huge village …sometimes you just need to be vulnerable to the people around you so they can help you. Parents are here to support you. It’s OK to be down, it’s normal, you haven’t gotten to the good part yet. Please keep going.”