Codependency is a broad term that is often times misused. It is not meant to be a label on someone that defines that person. In truth, we all struggle with codependency because we are all in some form of relationship. Codependency is a universal struggle. Codependency is simply the rejection of self. The challenges and uniqueness of codependency shows itself in how we are relating with other people in our lives.
In many ways, I think it is helpful to think of our codependency in terms of how we relate to another. Codependency shows itself on a large spectrum by one emotionally "retreating / hiding" or by becoming emotionally "aggressive / controlling". The most important thing to remember is that our style doesn't define us. Our relating style has developed through years of learning how to be with others. Most often, it was taught to us by our primary caregivers.
The real challenge and struggle in coping with codependency is taking new steps relationally. I liken it to experiencing "emotional detox". Relating differently to another person can absolutely produce anxiety. This fear is real and normal and usually has its roots in the fear of abandonment and rejection.
The role of therapy is to help identify, name, and learn new ways relating to others. It is a slow process but can be very beneficial because you end up gaining so much more of yourself than you ever realized was lost. The true is that we are made to depend on others and need others. Freedom comes by living out a healthy balance of interdependence and dependence on another.