Do you want to know what it’s like never to finish writing your work of fiction? Then simply self-edit as you write.
Do you want to know what it’s like to finish writing your book? Then be the author of your story, not the editor.
Self-editing* as you write will murder the creative process, and a dead story is a drag both to write and read.
* Sometimes, we reach a euphoric point in our craft where we glide along effortlessly in perfect syntax while simultaneously developing subtly sublime characters. We find the perfect pitch in our writing voice and never have to wrestle another flat adverb to the floor.
However. That season comes much, much later in your book. So stop self-editing, wait out the winter, and simply write, grasshopper.