My answer is likely to make you cringe. First, save your current manuscript under a different name, something like “Hope’s Draft Before Changes.” Then set your cursor at the end of the new beginning, delete everything from there to the end of the manuscript, and start writing from that point. Yes, rewrite it all from that point on.
From my experience, I have found that, in a situation such as yours, it is easier to start fresh rather than try to trudge through and tweak a mountain of text that no longer works. You might remember paragraphs here and there that do work, and you can copy them over from your previous draft, but with the old draft no longer in your way, I think you will find the going easier. And, of course, you can copy your ending back from your old draft, but you might find that you will create an even better one with this effort and no longer need the old one.
In writing, there is no substitute for hard work. Sometimes you just have to accept the challenge and march ahead.
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