In a PEOPLE's excerpt from her upcoming memoir, I Am Maria, Maria Shriver reflected on her divorce from Arnold Schwarzenegger, opening up about the "brutal" split from her husband of 25 years following the revelation of his affair.

Maria Shriver is opening up about loss and grief in a big way. In her new book I Am Maria — a collection of poems and reflections by the author — Shriver, 69, revealed she was unable to get off the floor of her hotel room after learning of her husband Arnold Schwarzenegger’s infidelity.

Arnold Schwarzenegger’s ex-wife Maria Shriver, who is the niece of the late President John F. Kennedy, is reflecting on their “brutal” divorce in her new memoir “I Am Maria.” Shriver Recalls ‘Brutal’ Divorce In an excerpt from her memoir that was obtained by People Magazine,