Hmm...to really know whether this is true or false, you have to know a little bit about Fitzgerald himself. Fitzgerald, like Gatsby, had an obsessesion with the wealthy. Most of his novels and stories revolve around the wealthy, and he worked hard for his place of acceptance among them. Although one side of his family had the wealth, the other side had (as they say) the breeding. So although Fitzgerald could sort of claim to be part of the upper-class society, he still was an outsider. In that way he was like Gatsby. Like Nick, Fitzgerald was from the Midwest, so he had the mid-western values that Nick shows.
To really see where these personalities combine to become combustible, one simply has to think about Fitzgerald's time in the Riviera. Fitzgerald and Zelda (his wife) quickly became friends with the upper class in the Riviera (like Nick with Dasiy and Tom) known for their extravagance, the FItzgerald's would throw huge, wild parties (like Gatsby). At these parties they would somehow (because of how drunk they were) do something to offend all of their new upper-class friends, and the party would end. It was definintly a battle inside Fitgerald to control and combine to live in peace with the two sides of his personality represented in The Great Gatsby, by Nick and Gatsby.