Have you recommended an ancient romance novel where the female protagonist has amnesia?

The female lead was a member of an assassin organization. Her code name should be No. 8. Later, she failed to assassinate the male lead and jumped off a cliff with another assassin. However, the female lead was saved by a branch before she died. Then, she lost her memory. Later, she was caught by the male lead and gave him a name. I forgot what it was. The female lead's memory loss was caused by some kind of drug that the head of the assassin organization gave her. After the female protagonist lost her memory, the male protagonist gave her the name. Later, they got married and fell in love. The female protagonist was arrested and found out that she was pregnant. Unfortunately, she lost her memory again and tried to assassinate the male protagonist again. In the end, the male protagonist found someone to detoxify the female protagonist and destroy the assassin organization.