So often in the writing and publishing of a book, things do not go as originally planned.
You might have planned to submit your book proposal by the end of last year, and now it is already three-quarters of the way through the next year, the proposal still unwritten, because life took an unexpected turn.
You might have thought you were on the final draft of your book, having invested in three full rounds of edits already, only to discover the book really wanted a different voice and now needs a wholesale rewrite.
You might have planned to upload your book to the printer a week ago — thought that was the drop-dead date for getting it back by the release date you've been planning all this time — and here you are, a week later, just now doing it.
I have to tell you this, dear writer: trust the timing. Every single time, I have seen the timing be what it needed to be.
If your proposal didn't get done last year, it's because it wasn't time yet. If your book needs a thorough rewrite and will take many more months to finish than you thought, it's because your book knows what it is doing. If you'd uploaded the book last Friday, you would not have received the unexpected graces that came in the days that have happened since, all of which make the book even better than it would have been a week ago.
Trust the timing, writer. All is unfolding as it ought to be.