When Tantalus went to hell this is what he suffered:
The punishment of Tantalus is to stand knee deep in water but be unable to slake his thirst because whenever he bends down, the water vanishes. Over his head hangs fruit, but whenever he reaches for it, it goes just beyond his reach.
Some accounts say that the water came to his chin but the point is that what he wanted was always right there, right where he couldn't reach it and it was that proximity that made his suffering so much worse. He was always dying of hunger and thirst without actually dying. His mental suffering is a matter of unrequited desire.
Really, I like the story of Tantalus a lot. In addition to giving us the word tantalize it is his story that is the origin of the idea of having chip on your shoulder. Rather than explaining that one, maybe you can figure it out and explain it in the comments. I will explain it later in the week if nobody else looks into it.