Thanks for the translation.
@Takaflame I'm gone do a reasonable assumption, she probably had feelings for him and at some point confessed to him, but he either rejected her or when she became a celebrity he broke up with her, or maybe it had something to do with his illness. Anyway, about her knowing about his illness, I doubt she does. She won't be treating him like that if she knows. And lastly, we can't unfortunately spoil the LN for you, since it's not translated at all, just the first prologue, and that's why I'm trying to make a logical assumption.
@RNDM_NPC unfortunately the LN was never fully translated, as I said above just the first prologue.