One of the very true things about teaching writing is it makes one become a grading efficiency expert out of necessity. There's just so much to grade. Compounding this is the fact that most beginning teachers tend to want to comment on everything.
Part of this is the "hey, I will give them the feedback I would want" factor. The problem with this is most grad students will be writing and rewriting because it's their job. Their professional development depends on rewriting until everything is as close to perfect as possible. Students, however, will never do that level of writing. The other factor at work is many people think commenting on every single line will make them appear to be that much more of an authority figure. This is important to many people, because let's face it. There's no one as insecure as a young teacher.
When you teach writing, however, you get 4-5 papers for every single student. Then there is the rough drafts, so you can double that number. Then there are proposals and outlines. If you try to comment on everything, you will, quite simply, go mad. The thing, though, is that students just don't need this level of commentary...nor do they want it. Page after page of commentary might actually do more harm than good; after all, students are people too (evidence to the contrary), and seeing nothing but grading marks is a bit disheartening.
My solution? I've gone to just a two page rubric. I read the whole paper in one sitting only. I check some boxes. I give them maybe 5-6 sentences. No conferences...unless they want one. This way, I can bust out 5-6 papers an hour rather than the 2-3 conferences I would do...or the 2-3 papers I would grade when I was the "pages of notes" instructor. The best thing about this, however, is the responses are pretty much the same in demeanor and judgement. And 98% of the students are equally happy. If someone wants more feedback...well, that's what office hours are for.
Lesson? Why kill yourself if only for your own ego? It need not be a requirement of teaching.