Looking for the title of this manhwa

So I'm looking for the title of this manhwa that I've forgotten about since it's been so long since an update.

The plot:
- The girl (female lead) becomes a doctor apprentice in order to improve male lead's health. She comes from an orphanage.
- Male lead (who's a heir to a duke) suffered from desnutrition and other health complication.
- It was later revealed that male lead was being poisoned by his uncle and cousin in disguise of bringing him medicine, because they wsnted ML to die so they could inherit the duke title.
- The female lead is hired as an apprentice by the family doctor, who happens to be her long lost father (they don't know about this fact).
- The doctor wanted to have an apprentice doctor so he could leave his position as a doctor and go search for his missing daughter. Not knowing his daughter was already in front of him.
- Doctor sometimes wishes the FL was her daughter. They are truly father-daughter, cause daughter is considered a medical genius, like her father.
- Thanks to female lead, ML starts to recover. And he starts falling in love. FL and ML are 12-14 years old.
- There's a time skip in which ML and FL was separated due to war. ML was sent to another country to recover but war begun and so they couldnt see esch other for 5 years.

That's all I remember. I hope this rings a Bell and we find the title.

Thank you!!
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