Courtney is expressing concern about a sudden and severe mental decline, suggesting it might be due to a serious medical issue like a tumor or another pathological condition. The quick deterioration has raised alarms about the possible physical cause behind the mental state.
He or she implies that the decline is not typical and warrants professional medical attention to diagnose the underlying problem. Visiting an internist is recommended to investigate whether a physical health issue is contributing to the rapid mental degeneration.