Venenum Invidiae

You create a toxic venom that causes deep envy in those it touches. Make a melee spell attack against a creature. On a hit, the target must make a Constitution saving throw. On a failure, the target becomes envious of everyone and everything around them, believing they are inferior. The target suffers extreme self-loathing, leading to self-harm. They take 4d8 psychic damage at the start of each of their turns until they die or the curse is lifted by a remove curse spell or a similar effect.