I've been writing for years. I'm happy to see anyone picking up the hobby; it's really fulfilling. In the past, I've mostly written novella-length stories. I can only produce a novel if it in some way involves a special interest of mine, as my last project did. I've never attempted to publish one, though - only short stories and essays. If you don't mind a piece of advice, I'd suggest that you find other books that center around a body-swapping conflict and read through them to learn which tropes those stories lean towards. It's the best way to turn out a really original piece. Good luck!
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I have not the kind affections of a pigeon. - Ralph Waldo Emerson