This has a similar plot of a normal guy dying and waking up in the novel he was reading, having to be nice to his enemy to avoid getting killed. The characters aren't identical though so you won't find the same dynamic. If that's what you were looking for, you can ignore this comment.
https://www.mangago.zone/read-manga/to_be_or_not_to_be/
aside from erha, idk maybe Im just tripping or being delusional but they semi kinda sorta remind me of bingqiu:
https://www.mangago.zone/read-manga/the_mutual_non_aggression_is_unpalatable/
https://www.mangago.zone/read-manga/to_be_or_not_to_be/ (someone already mentioned this in the reply so perhaps im not being delulu)
Are there any tropes like Luo Binghe and Shen qingqiu in any other stories? I miss them so much any suggestions?