I am not a therapist, but the brain likes things it knows. It goes towards what is familiar, and it doesn't matter if those familiar traits are good or bad.
Sure it could be a aftermath of what you enjoyed (or perhaps might not have) about your ex, but it will take time for you to process what you've been through. Its important to process, as to not enter a cycle of habits that may lead into wrongful projections on new people or heck, see their echoes everywhere you look.
I wish you luck though!