I'll echo

enlighten me's comments.
You miss what you thought was. But can I ask, do you think you miss who
you were when you thought she was that person you adored? Do you like yourself, how you feel about you, more now, or back then, when you first fell in love?
This is something I personally struggle with, as I'm sure many here also do. You were cheated on. Lied to. You were treated as "unimportant", like her being late, thats a lack of respect for you and your time. You were emotionally abused.
I realized, and this really helped me, that it wasnt just the fact that I romanticized about the ideal "her", the person I thought she was and would be, and the person I thought, or the life I would have, with her-- But that underneath the feelings of missing her (the object), and then focusing on her good qualities; what I had been ignoring was the "Me" aspect.
I missed who I was before her. Before I had been cheated on. Lied to. Emotionally abused. Called horrible names. Until her, that had never happened.
That "ideal time", those first 12 months, when all was great and I was great and we were great and so in love; I loved her, AND me. But after 4 years of absolute torture and neglect, being dehumanized in so many ways; I was not the ideal me any more.
So, that said, I think it's important to try to get back, as best we can, to our old selves. We have to live with the choices we made, and try to find ways to learn from what happened. To find meaning, in why these things happened, for a reason, to teach us. But also, we need to live the life of who we are - or were, before it happened.
You said you've learned a lot about codependency, why you were attracted to her, etc; and thats good. But make sure you remember that the you before her was likely a whole lot healthier; taking out what you've learned now, than who you are now.
I guess to sum it up, I think a lot of us feel our innocence was taken from us, by someone who never deserved to have us in the first place. And idealizing the good times, and her, the ideal her, is perhaps the last memories you have-
of yourself, when you actually liked
yourself.