Analyze the theme of Gatsby's loneliness in The Great Gatsby.

I think that you are probably going to want to go back
into the text and deconstruct his character a bit.  Essentially, you are going to want
to search for examples of how he remains distinct from everyone else.  While he might
throw lavish parties and spend inordinate amounts of money, he is not like Tom, Jordan,
or even like Daisy.  At all of the parties, there is something separate about him, as if
he is alone in a crowd.  He is a bit "off" from others.  Find this out, explore this
reason, and I think you have your essay.  This can take on many forms in terms of why he
is the way he is.  Perhaps, you want to focus on how Gatsby believes in the authenticity
of his convictions.  He genuinely loves Daisy.  Even if one wants to argue that he is
not really "in love" with her, but rather infatuated with her, at least it is a sincere
emotion that is arising from his own sense of being.  Unlike most of the others in the
social scene of the novel, Gatsby is not particularly interested with using people as
means to a specific end.  In this respect, he is different than the others who are a
part of this social configuration.  Perhaps, you want to focus on his own humble
background and how he never was fully able to escape this reality, a condition that made
him distinct from everyone else.  While he might have been able to deceive others, he
understood all too clearly that his background was distinctly different from others' who
had money in their past narrative.  These are broad strokes.  Using these as starting
points to find their inclusion in the novel might allow your thesis to be developed in a
more complete and thorough manner.