Am I in a difficult situation (haraj) for what I did, given that it was with her consent and the doctors recommended not informing her of the nature of her serious illness?

There is no harm in discharging a sick patient from the hospital if she is content with it and does not insist on staying for treatment, because medical treatment is not obligatory. There is also no harm in not informing her of her illness, based on the doctor's advice, to spare her psychological distress. It is recommended to abandon obsessive thoughts, seek refuge in Allah, ask for forgiveness for the patient, and show mercy to her.