Years ago I was encouraged to explore the Enneagram as a tool for self-understanding, personal and relational growth. If you know nothing about this powerful tool, I encourage you to learn about it. You won't regret it.
A good place to start is with a book by Renee Baron and Elizabeth Wagele, "The Enneagram Made Easy." This is a book that is clearly written and truly easy to understand. Knowing the Enneagram has been valuable to me in my own personal growth and in my intimate relationships.
Recently I encountered another book, "The Spiritual Dimension of the Enneagram: Nine Faces of the Soul" by Sandra Maitri. I am encouraging all of my clients to read a particular chapter in this book. It explains how we get separated from our essential and True Self. I've created a pdf of this chapter and you can find it here. It won't take you long to read it but the investment of your time will be well spent. Again, trust me on this.