Please help me remember the title of a novel where a female doctor was betrayed by her husband and son.

I read a novel a while back and forgot the title. I remember that the fmc was from a poor background and was married to a rich heir who was blind. She studied medicine and cured his eyes while being a housewife and raising their son. However, his first love returned and once he was cured both husband and son started taking her for granted. They went on outings with the other lady and the son started saying he wished she was his real mom while being a spoiled and rude brat to his biological Mom. They constantly humiliate her until she decides to divorce the husband and give up custody of the child. The husband and son assume she will come crawling back begging to take her back. Meanwhile she meets a man and his adorable nephew who cherish and protect her. He hires her for her medical expertise and becomes close with the little boy treating his as her own son and even attending his school events where her son humiliates her at first but after time starts getting jealous because she does the activities with the other kid and helps him with his school projects winning awards. The husband and son realize their mistake too late as they realize that not only was she the one who cured his blindness but is a talented and famous doctor who makes a name for herself. They go out of their way to get her back but moves on to form a family with the other man and his nephew. I don’t remember names other than the MC‘s nickname may be Cas.