I knew it! Reading too many novels/stories made me arrive to that conclusion too. She was acting too sus by making him hate her too much.
Yeah reading too many novels/stories made you capable of predicting many plot twist! I don't know if it already depict in the manhwa but one thing that make Dokja really hate his mother is because she never talk to him. He use to visit her when he was young and she said noting so he just talked about the novel the entire visit. While i dont remember the reason why she never talked, but i guess she's not saying anything to prevent her from reavealing the truth or show herself falling apart in front of his son. I truly pity Dokja's mother because she's doing everything that right to protect his son but make his live miserable instead.
This is a big spoiler so read it only if you really like spoiler
So actually, the one that kill the dad is Dokja by stabbing him with a knife. He did it to protect his mom that is getting beaten up by his dad. His mom make it seems like she was the one that kill the douch bag to protect Dokja mentally and physically. Because the trauma is so big Dokja memories of that day is very vague and distorted. There is 1 main reason she wrote the book, it's to make sure that people sees her as the murderer and erase all the possibility of anyone finding the truth that Dokja is actually the one who did it. But surprisingly the book became best seller and she gather a lot of money. While she was in prison, she entrusted Dokja to a relative and give them a lot of money for his living expense with the hope that it can ease his pain and suffering, unfortunately the greedy relative took all the money and never give it to Dokja so he suffer a lot by having no family nor money.
So yeah very complicated relationship, they somehow came to understanding but never fully recover their relationship.