Returning to the form of Stuff I've Been Feeling Lately, Sorry I Haven't Texted You Back is a poetic mixtape dedicated to those who struggle or have struggled with their mental health. Divided into two parts, "Side A" holds 92 poems, titled as "tracks," and "Side B" holds the "remixes," or blackout-poetry versions, of those 92 poems. The book includes the evergreen themes of love, grief, and hope. Named after Cook's viral Instagram poem, Sorry I Haven't Texted You Back lands in the crossroads of self-help and poetry.