unhappy vs suffering

unhappy is not a noun while suffering is a noun.

Word	Noun	Adjective	Verb	Adverb
unhappy	No	Yes	No	No
suffering	Yes	Yes	No	No

unhappy (noun)	suffering (noun)
	feelings of mental or physical pain
	psychological suffering
	a state of acute pain
	misery resulting from affliction

unhappy (adjective)	suffering (adjective)
experiencing or marked by or causing sadness or sorrow or discontent	troubled by pain or loss
generalized feeling of distress	very unhappy; full of misery
marked by or producing unhappiness
causing discomfort