JEALOUSY. Indeed the worst of emotions that could exist. It reduces you to this base, raw existence drawing out all the self-confidence, rationality and sense that you ever had. Changes your personality to that of a passive aggressive person with paranoia who is ever critical both intrinsically and extrinsically.
Jealousy. It blinds you. And it burns as it blinds you, consuming you, like a flame. Engulfing you in its wretched warmth. And when the flame dies down it leaves no ashes, just an eternity full of suffocating smoke and what's left of you.