If you can't see the truth clearly from your own standpoint, can you do it in the eyes of others?
I hope Gatsby has a happy ending, but it will be told from Nick's perspective.
Having said so much, it is actually a story about Gatsby and Nick exchanging souls. Of course, they will be exchanged back later.
PS: According to the content of the novel, Nick already knows Gatsby and has attended several of his parties, but Nick does not yet know the time period when Gatsby met Daisy.
Pps: Try to be as original as possible. In order to achieve this, the emotional scenes between Gatsby and Nick are not shown until very late, and they are only ambiguous. You can watch it as if it is without cp.