postpartum fatigue is not a condition but a symptom that can be caused by various factors such as physical discomfort, hormonal changes, or lack of sleep.

postpartum psychosis is a rare and severe mental disorder that usually occurs within the first 2 weeks after delivery and involves symptoms such as pronounced sadness, disorientation, confusion, paranoia, hallucinations, delusions, and thoughts of harming oneself or the infant.

letting-go phase is a normal stage of maternal role adaptation that occurs around 2 to 6 weeks after delivery and involves accepting the infant as a separate individual, resuming the pre-pregnancy relationship with the partner, and reestablishing relationships with other people.

According to the web search results, postpartum blues are characterized by feelings of sadness, lack of appetite, sleep pattern disturbances, feeling of inadequacies, crying easily for no apparent reason, restlessness, insomnia, fatigue, headache, anxiety, anger, sadness.