idk about the world collapsing plot (honestly i feel like there isn't even real, it just appears to be like that due to some people plotting against the emperor and her.... and i THINK she was given a chance so she could undercover the truth and avoid the death flags on her and her husband, but i might be wrong)....
i'm just amazed by the fact that she decided to ACCEPT the fact that she is a fake and her husband NEEDS to be with the real one, but doesn't ask the question "if i'm NOT the divine woman WHY God made ME come back and didn't use this power in the 'real' divine woman instead?"
I think with her logic she could've thought this as a punishment and a way to correct her sins of the past. She left the worst nightmare of her life, but it doesn't mean this one is much happier. Yes, the people she loves are still alive, but they're not the same people she knew; she's not the same person they knew. We've seen some moments of her expressing her sorrow towards the life she lost, the past that no longer exists, the memories that only she has, and although they are focused mainly on the Emperor, it must've hurt to see other people she cared about treat her so indifferently/with disgust/annoyance/etc - such as her father. We saw a short flasback of his smiling face of the past vs his stern/disappointed one. It must've hurt.
I understand your frustration, but I hope this perspective helps a bit. We know she blamed herself long before she died, and when one is used to that, it's a hard mindset to get out of (speaking from experience), no matter how much you think about things logically. Especially since all of her loved ones died before her in the past, adding that survivor's guilt.
She already thought the Goddess was punishing her in her past life. I'm not surprised she thought this was continuing that/giving her a chance to "atone" and "make things right", especially since she was sent to a point in time four years later than previously, with those four years having Anastasia acting like the og Anastasia, unlike her. If she was sent back and it was still a timeline where she got better in the beginning and things were good now, she may question about it more. Or she may not, being riddled with the guilt of the past/future that only she knows and the pain of knowing she cannot be with the one she loves most.
She's not wondering because she thinks the god sent her back immediately after she said she would live her life according to the novel and not try to get close to him she thinks because she was sent back immediately that that was the god agreeing with her thought which was a very valid thought process. It was a immediate response and it was directly after her kingdom was getting destroyed and their used to appeasing gods in that world.
Though I was highly curious why the new holy woman got thrown in to but I was thinking maybe the people who rebelled didn't care about either one and thought them equally guilty.
honestly, WHY she isnt wondering the reason SHE, the "fake" divine woman, came back idk how many times before the ending of the world and NOT the "real" divine woman?????