Madoka is being too rational for her own good. She cannot fulfill her (self-perceived)
role in their marriage, so there is no meaning for them to be together to her.
But that isn't what a relationship or even a marriage is about. Ryu doesn't care either.
He wants her back, fully and completely.
Madoka knows her own feelings still exist. She is just locking them away. She was able to enjoy
being his manager like she used to be, ignoring what came after.
Being faced with that again, however, her fear and sense of failure took over again.
Give in to your feelings. Koharu is only a straw-woman for your own conflicting emotions. Accept
that there is more to a relationship and marriage than just procreation.