No idea whether or not any stories out there address this issue but got the idea from how the actor played the werewolf character in the mini-series The 10th Kingdom.
If a lycanthropic character is not supported by a pack from the onset of their dual nature changes, then odds are that the changes would result in severe mental instability that could show up in many different ways. A lot of stories have "the murderous" lycanthrope trope but I can see many other ways the instability could materialize. I would be interested in a story that showcased a lycanthropic M/C that had to deal with that especially if the story had other lycanthropic side characters with their own instabilities.