What do I do if my coach wants me to do each line a certain way?

I feel that is a problem. I call it manipulation. When a coach is new to the field of coaching, it is normal to try to manipulate an actor into giving a great performance. However, seasoned veterans will generally act as a guide for the actors and teach you how to listen to your own voice. They will teach you how you can make your own choices by giving you clear steps and a solid foundation to use. Then they will want you to free yourself from the technical side of things and let go in your work and 'live' moment to moment.