Whatever he was, he had quite the hurricane marriage with Zelda whom I suspect to be IEI. He wouldn't allow her to publish stories about their marriage as they were "his" material. He had a love-hate relationship with Hemingway who was most likely LSI.

Fitzgerald was widely known for his drunken public appearances and his attempt to live the very lifestyle that he criticized in Great Gatsby. It's funny that in his younger years he seemed to be like Gatsby, but in small ways became like Tom.

XIE 3w4 Sx/SP is a good guess with me leaning slightly towards EIE.