YOU SAID:
I wish I had my book.
INTO JAPANESE
私は私の本を持っていた希望します。
BACK INTO ENGLISH
I had my book I want.
INTO JAPANESE
私は自分の本を持っていました。
BACK INTO ENGLISH
I had my own book.
INTO JAPANESE
私は自分の本を持っていた。
BACK INTO ENGLISH
I had my own book.
Come on, you can do better than that.