Jealousy

Just when you think it can't get any worse,
Envy penetrates your soul,
And fills you with a rancor you didn't know existed,
Leading you down a path that was better left untrodden,
Only, you don't know how to run from the intoxicating hatred.
Useless if you resist responding to the beast raging within,
Seemingly devouring you from the inside out until,
You do something you regret.

"The jealous are possessed by mad devil and a dull spirit at the same time" 
- Johann Kasper Lavater, Swiss theologian and poet