I’m Glad My Mom Died begins as Jennette McCurdy retells the story of her early life and childhood in Garden Grove, California, where she grew up, kept company by her mother, father, maternal grandparents, and three older brothers. When Jennette is only two years old, her mother, Debra, is diagnosed with stage four breast cancer. This completely alters the dynamic of the family, and they assume that Debra is going to die. Though her cancer goes into remission, Debra’s illness left a long-lasting impact on Jennette, who made it her purpose in life to keep her mother happy.

When Jennette is six, Debra coerces her into becoming a child actor, as Debra herself once dreamed of acting professionally. Jennette does not enjoy performing but wants to make her mother happy, so she agreed to give it a try.

Over the next several years, Jennette developed a growing resume of small roles and guest appearances in commercials, television shows, and movies. She became known for her ability to “cry on cue”—a coveted skill among child actors. However, the stress of auditioning and performing overwhelms Jennette, and she starts to complete intricate rituals to help calm herself down, something that her grandfather and, later, Jennette herself attributes to undiagnosed Obsessive Compulsive Disorder. 

Body image also became a concern for Jennette. As a child actor, she was praised for her youthful appearance and childlike figure. When she notices her breasts beginning to develop, she panics, asking Debra how to stop it from happening. Debra then teaches Jennette about “calorie restriction.” Although doctors and other adults express concerns that Jennette is losing too much weight and exhibiting anorexic behaviors, Debra is dismissive and ignores their worries.

The major turning point in Jennette’s acting career comes when she is cast as one of the stars of the Nickelodeon children’s sitcom iCarly. Although the money Jennette earns from iCarly helps the McCurdy family achieve financial stability, it also puts Jennette in many uncomfortable positions, such as being forced to experience her first kiss on camera. It also introduces her to The Creator, an emotionally and verbally abusive man who oversees production on the show. He takes an interest in Jennette, even promising to write her a spin-off series once iCarly ends.

During a hiatus from iCarly, Jennette briefly pursues a career as a country music singer. However, just before she leaves to go on tour, her mother’s cancer returns. Debra insists that Jennette goes on the tour without her, marking the first time Jennette has been away from her for more than a few hours. Freed from her mother’s constant supervision, Jennette begins binge eating, and she is ashamed of the weight she gains—as well as her mother’s eventual reaction to her bigger body.

After returning from the tour, Jennette is disturbed by how frail her mother looks. Debra insults her for gaining weight, and Jennette promises to begin dieting again. Since Debra is now too weak to drive Jennette to and from the iCarly set, the studio arranges for Jennette to have an apartment in the city. However, Debra is distraught over the prospect of separation, and she ends up sleeping over at Jennette’s apartment most nights.

Jennette begins dating Joe, a much-older man she met while working on iCarly. This relationship—and Jennette’s efforts to hide it from her mother and the press—causes a rift between Jennette and Debra. After photos surfaced of Joe and Jennette on a secret vacation in Hawaii, Debra sends Jennette a tirade of texts, voicemails, and emails insulting her character and threatening to disown her—punctuated by requests for money to replace a broken refrigerator. However, when Jennette next sees her, Debra pretends as though the incident never occurred. 

As Debra’s health declines, it becomes apparent that she will likely die soon. Jennette breaks up with Joe, having fallen out of love with him. She also begins drinking heavily, using alcohol to suppress her grief over her mother’s condition.

In the aftermath of Debra’s death, Jennette spirals into a cycle of grief and unhealthy coping mechanisms. She is miserable at work, having agreed to star in an iCarly spinoff called Sam & Cat. She resents the role, feeling that it is childish and unfunny, and she is especially bitter when the network executives at Nickelodeon renege on their agreement to let her direct an episode of the show. Her drinking continues to worsen, and she also develops bulimic tendencies, engaging in bouts of binge eating followed by purging, or vomiting.

Jennette is used as a scapegoat by the network when Sam & Cat is canceled, with the producers pushing the narrative that she was jealous of her co-star, Ariana Grande. However, Jennette is just excited to be free of Nickelodeon, enabling her to pursue more adult projects.

While on set for a new Netflix series, Jennette meets Steven, an assistant director. The two begin a romantic relationship, with Jennette remarking that Steven is her “first real love.” However, after discovering Jennette’s bulimia, Steven gives her an ultimatum: seek treatment, or he will have to break up with her. Jennette pursues therapy, but she quits after her therapist, Laura, begins probing into her relationship with her mother.

Steven is surprisingly fine with Jennette quitting therapy, having undergone a sudden religious conversion. He begins bringing Jennette to different church services and takes a vow of celibacy, both of which irritate Jennette. Adding to her stress is the sudden revelation that the man who helped raise her, Mark, is not her biological father. Jennette is upset that Debra never told her about her true paternity before she died. However, when she tries to discuss the matter with Steven, he reveals a shocking secret of his own: he believes he is the reincarnation of Jesus Christ.

After losing a tooth while vomiting, Jennette reflects on the miserable state of her life. She decides to seek treatment for her eating disorder and mental health issues. Steven is also diagnosed with schizophrenia, and Jennette attempts to help him work through the aftermath. However, while Jennette is making progress, Steven begins to stagnate, lapsing into a marijuana addiction that leaves him listless and unmotivated. She ultimately decides to break up with him, prioritizing her own wellness.

Jennette’s journey toward recovery is long and frustratingly nonlinear. Over the next several years, she makes continuous strides toward developing a healthier relationship with food, guided by her therapist, Jeff. She also begins processing and unpacking the trauma of her childhood, including the abuse she suffered at Debra’s hands. This culminates in her decision to quit acting altogether and instead pursue a career as a writer. The memoir ends with Jennette visiting her mother’s grave and reflecting on the tendency people have to unduly glorify and romanticize the dead.