It is a process, a gradual change, and won't happen overnight. I recently had a couple of discussions on the difference between love and codependency. They are really quite similar, but love should continue to be a positive emotion. If you recognize you are defended a lot of the time, and adopting the codependency behaviors again, recognize that it isn't about love. I do think that in order to learn to experience love in a relationship, you have to learn to battle and overcome codependency.
Recovery is a spiral, two steps forward, one step back.
Sometimes it is two steps in each direction, and unfortunately sometimes it is two back and one forward. If you keep working at it and are making no progress, maybe it's time to see if you are in relationship with another addict or an unrecovered codependent.