Stella was also laying in a hospital, with Alex beside her.
She's tired of waiting and not hearing anything from Diana. Coupled with the dream she had about how Diana was dying, she jumped into conclusion and refused to eat, drink and live normally, without knowing if Diana is still alive.
She has been hospitalized and only holding on, because of Alex that's also broken.
Alex would have assured her that everything is fine, but he has searched and couldn't find Diana as well.
The only source to know how she's doing is Nathan, but ever since Aroma left him, he just kept taking missions upon missions and refused to give himself rest.
Within a month, he has executed two dangerous mission, which the second one nearly got him killed.
He didn't answer any calls and usually lock himself up, while the nominees for his position were in charge of the decision making.