Ask for the name of a novel

The story went like this: A big boy fell in love with a married woman. This married woman was actually very unhappy. Her husband was very bad to her. Although she found some comfort in this big boy, their love could not be accepted by today's society. Because she could be said to have watched this big boy grow up, the age difference between the two was actually very big. Moreover, there was always a girl who was loyal to the big boy. There were too many barriers between them. Although they loved each other, they had never crossed the line or broken through this relationship. Finally, one day, the boy doted on this married woman and hugged her tenderly. When he was seen by her husband, they ran to the river. In the end, the boy had no choice but to swear to the heavens that as long as they could be together, he would pay any price. Then, they hugged and jumped into the river. In the end, They returned to the ancient times together. The souls of the two people possessed the young master and young lady of the two large families in the ancient times. However, these two young masters and young ladies were not good people in the society at that time. The reason why they could possess them was that at the same time, these two people were on the verge of "death", and the two of them could use their bodies to survive. However, the bad young master was not completely dead. His soul still existed. In other words, the big boy in modern times shared the same body as the young master in ancient times. Therefore, the big boy couldn't control his body completely. Every time he saw the young lady who was possessed by the soul of a married woman, he would make his mood and personality erratic. Additionally, the young master in ancient times was too evil. He thought that he was so erratic because of this young lady. Therefore, he tricked her to the edge of the cliff and wanted to kill her. At this time, a swordsman happened to pass by and saved the young lady. He beat the young master seriously and completely destroyed the bad young master in the body. The body finally belonged to the big boy. However, because the swordsman was too heavy, the new body did not recover. Although it would not die, it would be very weak from then on. "After that, many things happened. For example, the husband of the married woman and the girl who fell in love with the big boy also came to ancient times. There were a series of dangers. I can't remember them clearly. I don't know if anyone has read the book in such detail. I hope you can tell me the title and author. Thank you in advance.