What should I cover in a ten page essay on a therapy theory (that I make up myself)?

Bascially, our assignment is to type up ten pages on a therapy we make up ourselves. I have in my head the jist but I feel overwhelmed in what to include.

My theory: A person has life experiences which shape how they think, feel, and behave. It is up to the person to recognize these things and to choose for them to shape them in a positive or negative way.

Now: With that theory in therapy–I must come up with ten pages. Help!