I think these may match:
A Journey to Love
FL is a contract killer and ML is also a killer but for the emperor, they love each others and protect each others in secret, sometimes they're in clash because of the different thinking. And yeah ML usually getting hurt by FL's behaviour and tells her about it at times. BE
Love Like The Galaxy
FL's hiding all her pain and trying to solve problems on her own but ML always know and solve the problems for her and ML often ask FL about what happen and to tell him everything. They're sometimes in quarrel because of FL's behaviour while FL getting angry because she feels several unlucky situation happens because of ML's family and position. HE
My Cherie Amour
FL always try to protect and make ML happy in secret, but ML always tell FL not to solve his problems for him on her own and not to decide what makes ML happy or unhappy and that he feels useless when FL's like that. HE
Romance of Tiger and Rose
FL is a transmigrator and the novelist of the world she entered. She has her own prejudice towards ML as a novel character so she treats ML like the original novel character and try her best to make the novel ending like it should so she could come back to real world. It hurts ML and ML confront her at times. HE in real world
The Princess Royal
FL and ML are both rebirth. FL is a proud princess while ML is counted as commoner who enters officialdom. Both are trying to protect each others in secret but ML getting hurt from time to time over FL choosing to cooperate with others (including a love rival) without his knowledge. Sometimes they're in quarrel. HE
