A 28-year-old woman presents to the PMHNP for an evaluation of "crying spells" associated with her recent move to the area. She moved across the country approximately 2 months ago to accept a new job. She states that she cries every day after getting home from work. She is confused by this reaction, because this was a "happy" move for her. She misses her family and friends, but she does not regret the move in any way. What is the most likely diagnosis?