Not a therapy book, but my previous therapist (who was generally very gentle and well meaning) recommended Hilary Mantel Beyond Black to me. She recommended it because it addresses the trauma of childhood sexual abuse which is facilitated by the child's mother, something I experienced. I am not delicate, I don't really support stuff like trigger warnings, and it is an excellent book, but bloody hell it was a tough read for me. I frequently wondered how she could have casually recommended something so brutal, it was very out of character for her. I didn't get the chance to discuss it with her because I ended the work shortly thereafter (not related to her literary choices!). It is very relevant to me and asks some really intelligent questions about trauma, delusion, healing, and I am glad to have read it so maybe she was onto something.