Final answer:
The character who confides in Nelly Dean about her uneasy feeling after making an important decision is Cathy from Emily Brontë's 'Wuthering Heights'. She is torn between her love for Heathcliff and her marriage to Edgar Linton, which she feels in her soul is the wrong decision.
Step-by-step explanation:
The character who consults Nelly after making an important decision and feeling a strong foreboding is Cathy. This is a reference to Wuthering Heights by Emily Brontë, where the character Catherine Earnshaw, often referred to as Cathy, struggles with her feelings and decisions concerning her love for Heathcliff and her eventual marriage to Edgar Linton. The decision that causes her such distress is her choice to marry Edgar over Heathcliff, which she confides in her nurse, Nelly Dean, as something that she feels in her soul to be wrong, despite making it for practical reasons.
This character's turmoil and the consultation with Nelly reflect the themes of passion versus societal expectations and the conflict between what the heart desires and what is deemed as socially acceptable choices.