While editing is a perfectly valid source of inspiration, it can easily become a way to waste time. If your goal is to get down as many words as possible, you may be better off simply glancing over what you wrote last time and then moving right along.
On a first draft, repetitive editing is often easier than writing new material because the words you are editing already exist. Those words are safe, written, and proof of your ability to write… something. By moving on, you might write off track, write badly, or write nothing. Scary thought.
But if you go off track from your plan, sometimes your imagination is on to something. It may be exploring a previously unnoticed facet or possibility in what was already created. If not, you can start over – saving the tangent in your scrap pile a possible fodder for another book, of course.
And if your new words are not very good, it’s alright. First drafts are for getting the ideas down. As long as you what you write makes sense and you can follow the inner and outer action, you’ve done well. If you think that you will not be able to come back later and understand what you have written, then it is time to edit. Add whatever is needed for a casual reader to make sense of thee action.
What if you can’t write at all? Take baby steps. Give your character a goal based on the outcome of his last conflict (there was some kind of failure, upheaval, or revelation, right?) Brainstorm ways your character can trip himself up when presented with opposition. While you write this, you may get part-way through and have a better idea. Just shuffle the fragment into your scrap pile and keep writing.
Just keep moving forward.