Depression

depression
dɪˈprɛʃ(ə)n/
noun
1.
feelings of severe despondency and dejection.
"self-doubt creeps in and that swiftly turns to depression"
synonyms: melancholy, misery, sadness, unhappiness, sorrow, woe, gloom, gloominess, dejection, downheartedness, despondency, dispiritedness, low spirits, heavy-heartedness, moroseness, discouragement, despair, desolation, dolefulness, moodiness, pessimism, hopelessness; More