[2] All proceeds from the song are donated to charities that address the stigma of mental health, including Time to Change and Beyond Blue.

Written in first person, Sad Forever discusses living with multiple mental health conditions and the social stigma surrounding them.

Specific topics include Lauv's experience with depersonalization, grief, insomnia, and the usage of psychiatric medication.

Lauv premiered the song during the Manila Leg of his Asian Tour on May 20, 2019 at the Smart Araneta Coliseum and eventually shot the music video in one take afterwards.

During the concert, Lauv stated that "This is officially the biggest headline show that I ever played," and he wanted to have the video shot in Manila.