Harry could be heartbroken. He might isolate himself for a while, not wanting to see anyone or do anything. Just staying in his room, crying and reminiscing about the good times with Edward.
He could be devastated. Edward is deeply in love with Bella, so he might go into a state of depression. He may isolate himself from his vampire family and friends, constantly replaying in his mind what went wrong in their relationship.
Perhaps they are characters in a modern - day wizarding world where they are both part of a secret magic society. Edward could be a powerful wizard from an old family who feels threatened by Harry's new - found powers. So, he decides to break Harry's heart to assert his dominance.
Bella may react by trying to understand Edward's reasons. She could be more rational in some fanfictions and instead of just being sad or angry, she starts to investigate. Maybe she discovers that there are forces at work that she can fight against to get Edward back. Or she could decide that she doesn't need him and focus on her own growth and development, becoming a stronger and more independent person without him.
Well, in the fanfiction, if we consider the people around Harry, the teachers at Hogwarts could be concerned at first. Dumbledore, being the wise figure, might see potential in the baby and encourage Harry. As for Edward's friends in the vampire coven, they would have mixed feelings. Rosalie might be jealous as she always wanted a normal life with a baby. Jasper might be worried about the baby's influence on their coven's stability. But overall, as time passes, they would adapt and form a new kind of community around the baby.
Well, it could be that Edward, perhaps jealous of Harry's popularity or a girl he likes, spreads false rumors about Harry. This causes Harry to be ostracized and his heart to break as he loses friends and respect.
Harry might be initially shocked and angry. After all, his wand is an important part of his identity as a wizard. He could lash out at Hermione immediately, demanding an explanation for her actions.
Some in the wizarding community might be shocked. Harry is a hero, and they expected him and Hermione to be together forever. There could be a lot of gossip and speculation. People might take sides, with some blaming Hermione for breaking Harry's heart.
Draco might become withdrawn. He could isolate himself from his friends and spend more time alone in the Slytherin common room, brooding over what Harry has done to him.
In some fanfictions, Harry might become very angry. He might feel that Ginny is being unfair or not understanding his situation. This anger could lead him to say things he doesn't really mean in the heat of the moment. However, deep down, he's really hurt and confused.
Ginny might be initially heartbroken. She could lock herself in her room and cry for days. After all, she loves Harry deeply. But then, she might become angry and start to focus on her own life more. For example, she could throw herself into her Quidditch career or her studies at Hogwarts.