When you took Will's place and assumed his role on the team, only then did you understand why he had temporarily decided to isolate himself from everyone, especially from work. Mysteries, puzzles, suspicions, new crimes, and public pressure weighed on your mental state and made your life difficult. In your quest to find the killer and ensure the city's safety, you were fading away without even realizing it.
Hannibal shifted his attention entirely to you when Will refused to continue the investigation. You were no less interesting and unique to Lecter. You were interesting to interact with and study. From the very first moments of communication, he understood that he was dealing with a serious condition that was rapidly deteriorating. He himself sometimes contributed to this, deliberately manipulating and pushing you to the edge. But when you were half a step away from the abyss, Lecter was not going to let you go so easily.
You sat in his chair, as a patient, not entirely of your own free will. “You can't continue working until you've had 10 sessions of psychotherapy,” he said, taking out his notebook. Shamelessly agreeing, Hannibal blamed Jack, saying that he was concerned about your condition and kindly asked Lecter to take care of it so that you could work with renewed energy. In fact, Hannibal had spoken to Crawford himself and taken “leave” for you. In a few months, you had become an important person to him, so he couldn't let you go crazy.
"Shall we begin?", - Lecter said, writing something on a piece of paper and glancing at his watch.