Meaning: He experienced unhappiness or sorrow after the loss.
Choice of Words: Felt sad is a verb phrase which means to experience unhappiness or sorrow.
Alternative Expressions
He was filled with sadness after the loss.
Meaning: This sentence means that the subject was deeply saddened by the loss.
Choice of Words: The word "filled" suggests that the subject's sadness was intense and overwhelming. "With" is a preposition that indicates the presence of something, and "sadness" is a noun that refers to the emotion of unhappiness or sorrow.
The loss left him feeling downcast.
Meaning: This sentence means that the loss caused the subject to feel sad and discouraged.
Choice of Words: The word "left" suggests that the loss had a lasting impact on the subject. "Downcast" is an adjective that describes a state of sadness or depression.