Both Jay Gatsby and his creator F. Scott Fitzgerald share many similarities, demonstrating that there is much of the writer in his seminal work The Great Gatsby.

Both Gatsby and Fitzgerald were born in the North: Fitzgerald was from Minnesota, and Gatsby came from North Dakota. Both men enlisted in the Armed Services and became officers. As a second lieutenant in the infantry, Fitzgerald was stationed at Camp Sheridan in Montgomery, Alabama; there he met a young and beautiful woman named Zelda Sayre, the daughter of an Alabama Supreme Court judge. Gatsby was a young officer in the infantry, as well, and while he was at Camp Taylor, he met Daisy Fay, a debutante from a patrician family in Louisville, Kentucky. 

After the war, Gatsby came back to the states and moved to New York, where he made his money as a bootlegger; he then moved to West Egg, hoping to regain Daisy by means of his wealth. Fitzgerald returned to the states after the war and moved to New York, hoping to have a career in advertising that would be lucrative enough to persuade Zelda to marry him. 

When Fitzgerald earned celebrity standing from his writing, he adopted a lavish lifestyle; likewise, Jay Gatsby lived in a mansion, where he threw lavish parties and attempted to lure the rich and famous. Both men became caught up in the fast-paced and decadent Jazz Age, and their lives deteriorated. In his narrative "The Rich Boy," Fitzgerald wrote, "You've got to sell your heart...." Jay Gatsby certainly did this.

Indeed, it does seem fitting that Fitzgerald's tombstone bears the final words of the novel The Great Gatsby:

So we beat on, boats against the current, borne back ceaselessly into the past.

A thesis statement can draw parallels between the character and the author, expressing the idea that there is much of the soul of F. Scott Fitzgerald in his main character Jay Gatsby as each seek the American Dream, but they fail because they seek material gain and social position at the expense of their inner spirits.

Jay Gatsby and F. Scott Fitzgerald are similar in the following ways:

-They are both from the Midwest (in the novel, a place which represents Idealism and old-fashioned values).

-They both love women from Old Money families, families which would never have approved of their daughters' lovers.

-They both attended prestigious universities but did not complete their education.

-They are both World War I veterans.

-They both throw extravagant parties.

-They ultimately meet with disillusionment with the American Dream.

As for your paper, in your introduction, you could discuss how authors often pattern their characters after themselves and their own experiences.  Of, you could discuss the original version of the American Dream and how that version has changed throughout American history.

Your thesis statement needs to be one sentence (not a question) and should discuss the fact that Gatsby and Fitzgerald share characteristics.  You could clean up your statement above about Gatsby being a symbol of Fitzgerald and use that for your thesis statement.

Good luck!