I have a strong stress reaction to just thinking about opening the files (ETA: it's thinking about doing the work that causes the reaction; opening the files is just the first step in actually doing the work)

This looks like a severe burnout. Is it possible for you to take a month off?

Have you tried 80/20ing the drafts? What's the most difficult task that you need to perform to complete the papers? Does it require hard mental work, or it's just formatting / proofreading / editing / rewriting / reviewing sort of thing?

Or perhaps the task itself isn't what paralyzes you, but you're afraid of some submission / approval process that lies ahead? This has often been the case for me when I dealt with submissions of important work to human reviewers. I'd suggest a written self-interview to figure out what really causes your reaction.