Some popular Naruto and Sakura angst fanfictions include 'Heartache'. It explores the emotional turmoil between them when Sakura realizes she might be losing Naruto to his new responsibilities. 'Unspoken Pain' is another. It shows how they both have secrets and pain that they don't share with each other. 'Grieving Souls' is also a great read as it focuses on the times when they are both dealing with the loss of comrades and how it affects their relationship.
The popularity of Naruto and Sakura angst fanfictions comes from the fact that fans are always interested in exploring the what - ifs. What if their relationship had more problems? What if they couldn't be there for each other? These fanfictions allow for a more in - depth look at their characters and how they would react in difficult situations. Also, the angst adds a layer of drama that many readers find appealing.
A common theme is unrequited love. As mentioned before, the original dynamic between Naruto and Sakura had elements of this. In fanfiction, this can be exaggerated, with Naruto pining for Sakura who is still hung up on Sasuke for a long time. Another theme is sacrifice. Writers might create situations where Naruto or Sakura has to sacrifice their own happiness or even their lives for the other. For example, Naruto might sacrifice his chance at becoming Hokage to save Sakura. Also, misunderstandings often play a big role. They could misinterpret each other's actions or words, leading to more angst in the relationship.
Sakura would probably be angry at herself for being captured. She's a proud ninja. So she would start looking for weaknesses in Itachi's hold on her. Maybe she would try to engage him in conversation to find out his motives, all the while formulating a plan to break free. She could also try to send out some sort of signal to her comrades if possible.
She would be both curious and empathetic. Curious about how the baby ended up where she found it and empathetic towards the baby's situation. So she would start to form an emotional bond with the baby right away. She might talk to the baby softly, trying to soothe it, and then start making plans on how to best care for it in the long run.
Another reaction could be that Sakura tries to follow Sasuke. She believes that she can change his mind or that she can be of help to him. She might leave her own responsibilities behind for a while to chase after him, thinking that their bond is strong enough to overcome whatever is making Sasuke leave.
In some fanfictions, Sakura may be determined to find Sasuke and bring him back. She could set out on her own journey, facing various challenges along the way, and growing both as a person and as a ninja in the process of trying to reunite with him.
She might be heartbroken. Sakura could initially be in shock and then fall into a deep sadness. She may blame herself for Naruto's leaving, thinking that she could have done something differently.
Sakura would be over the moon. She would blush deeply and look at Sasuke with so much love in her eyes. She might be at a loss for words for a moment, but then she would find her voice and tell Sasuke that she has been waiting for this moment her whole life. She would also feel a sense of pride that Sasuke has chosen her, after all they have been through. And she would immediately start thinking about how to share the good news with their friends, especially Naruto, who has been like a brother to her and has also been a part of their journey.
Sakura might be initially frustrated. She's used to Sasuke being in control, so seeing him drunk could be a bit of a shock. But then she'd probably feel a sense of protectiveness and try to sober him up.