She wasn't a very good doctor
Aside from breaking rules, and crossing lines, she just seemed really miserable and disconnected in sessions with her other patients.
She never responds to things they say or questions they ask. And I really thought that by the end of the movie they would explain WHY she is, as Mr Jones observes so sad.
But who knows! Either way, trying to turn this into a love story was a really weird choice. They could have acknowledged that feelings were there, on both sides, but decided to keep it professional and realistic.