Translation:When I am hungry, I always am discontented.
"Discontent" is not correct here because it is a noun, e.g. 'there was growing discontent among the workers". "Discontented" is correct here because it is an adjective describing the person's feelings. However, it is an awkward choice of word. I used "unhappy" when doing this exercise, and this was accepted.
Discontent is an adjective as well as a noun. It us however used far more often in English as an adjective.
Did you mean "Mi malŝatas esti malsata"? ("I don't like being hungry").
What does "hangry" mean? A typo for "hungry" perhaps? But then what's the point of writing two Esperanto words and an English one. Sorry if I'm being slow, but I just don't get what you mean.
Because "sad" in Esperanto is "malfeliĉa". "Malkontenta" means discontent or discontented, both of which, incidentally, can be adjectives according to the English dictionaries I have looked at. (The email I received notifying me of your post said that your message was "discontent is a noun, discontented is an adjective". You must have changed it.) Also, for "whenever", Esperanto uses "kiam ajn" - "kiam" by itself just means "when".