I write short stories in Chinese, and give a new page to my teacher to correct every few days. This is the story I'm thinking of writing:
We have a male main character. His wife is devoted to him, but he's needy and kind of an asshole. His personality changes wildly and unpredictably. In particular, he does not want his wife spending time with her friends.
Plot twist: he died two years ago: the male protagonist only exists in his wife's imagination. He's not only not an asshole, but he died rescuing his wife.
We now have a female main character (his wife). She has not managed to come to terms with his death; she imagines he's alive, and projects her feelings onto him. His wild personality changes stem from her uncontrolled grief-motivated mood swings. Her friends want to help her, but she's not ready, so her (imaginary) husband blocks her. She blames herself over his death, and tries to find redemption through satisfying his (imaginary) needs.
I'm not sure how I can do this, or even if this is feasible. I'm worried that the reader will become "disconnected" because of the change of protagonist.
I'm wondering if the Writers.SE readership could highlight some precedent, i.e., prior stories along these lines, where there was a major shift from the original protagonist to a second protagonist.
Question: How can I successfully change main character half-way through the story?