That struggle is raw, Kylie. I can relate to that deadline dread. But that must be your focus now.
I'm not typically quoting boxers whose sport is to bash each others' brains to pulp, but here is one from Muhammad Ali:
"A winner is a dreamer who never gives up."
You are the one that never gives up. It shines through your writing.
Maybe a stupid idea (I have so many of them): can't you share some chapters of your book as articles on Medium? Ask for your readers' comment. That would kill 2 birds with one stone: you write on Medium and grow there WHILE writing your book.
But probably it's a stupid idea.