Productivity vs Progress

I have been struggling with my productivity these past few weeks, so when I came across a tweet yesterday which said one should look at progress and whether one feels fulfilled, not productivity. Productivity is a physical metric--number of words, chapters, etc.--whereas progress is more subjective. I would say I am making progress, even though it isn't showing yet in terms of physical output. Do I wish I was progressing faster? Sure, who doesn't? But, I am not wracked with guilt over not spending enough time working or feeling stuck because no wheels in my head are turning. Keeping faith in myself is difficult at times, believing that there will be a stonking PhD at the end of this tunnel. But, trying to complete a project like this in the middle of pandemic, spending month upon month working in the isolation of my bedroom requires oodles of faith.