What to expect, breaking up from a narcissist:
To begin with, you will still think about yourself the way he does. He will totally be in your head, telling you how to think. It takes a lot of time and critical thinking to decide what your thoughts about yourself are. One gut reaction can be to think the opposite he did, and that's cathartic for a while, but it's only when you can sift through objectively and decide what is you and what isn't that you're making the break.
Initially, you will wonder what he's doing and if he's thinking about you all the time. Your thoughts will still be filled with him. Thinking about yourself, not in connection with him, is an important skill to relearn. Treat yourself to things that you like. If you even know what you like any more... If you don't, fill your thoughts with that. Try things out.
Progress will be in stages. You'll think you're doing well one day and then the next you'll suddenly remember something you'd forgotten, or realise something was very wrong in your relationship that you'd just accepted as normal. It will be a rollercoaster ride of emotions. You've probably been suppressing your emotions because he's told you how to feel, that what you feel is wrong. In which case, just feeling things strongly can take a while to get used to. Accept the feelings, let them wash over you, wait and they will die down again. They're useful. They indicate something not right. They help you stay away from similar characters in the future.