I did it. I took a night off. Mostly. I did check some email and worked on a figure for a review, but I actually went to bed on time. I didn't spend the night tweaking a personal statement or editing some random text. And it felt good.
I guess I needed a break from my self-imposed marathon to help refocus and reconnect with my family. Lately I've kinda felt like I've just been in the same room with them thinking my "great" thoughts. Or worrying how I'll be able to get everything done.
While I've been productive, I came to the realization that if I didn't start getting at least 5 hours of sleep soon it really wouldn't matter - no matter what I achieved, there's no chance in hell I'd be able to sustain it, much less be happy in life.