There is more going on here than Lyme disease.
That may have been a trigger. But... it sounds more like MI than physical. Yes, she has a physical problem. But her reactions to it are not normal... Know what I mean?? Perhaps she was "closer to the edge" than any of you realized, with the pressure of her master's degree and all. This may have happened anyway.
But she doesn't want help. And that isn't uncommon with MI.