I've finished my essay on hell now. It turned out that one of the key questions was what people were like in hell. Here are some quotes on that which I found helpful.
To enter hell is to be banished from humanity. What is cast (or casts itself) into hell is not a man: it is ‘remains’.
C.S. Lewis, The Problem of Pain
When human beings give their heartfelt allegiance and worship to that which is not God, they progressively cease to reflect the image of God... it is possible for human beings to so continue down this road.. that after death they become at last, by their own effective choice, beings that once were human but now are not, creatures that have ceased to bear the divine image at all... they pass simultaneously not only beyond hope but also beyond pity.
Tom Wright, Surprised by Hope
Sometimes people ask me: "In heaven how can I be happy, knowing that my fellow human-beings - maybe the people I love best - are in hell?" And the answer is simple. No human being will be in hell. The creatures in hell are not human beings any longer... The person you knew and loved will not be in hell. That person had so many lovable qualities - the remnants of the image of God - but now, the image of God has been obliterated... You could not love the creature in hell if you tried - God cannot love that creature - there is nothing there to love.