Schedule, and stick to it! It's exceedingly important to take time off, no matter how tight your deadlines are. Generally, if I can't work yoga in at least a couple of times a week and a bit of time at my craft desk every evening, then I know I'm in danger of burnout. Decide how many hours a day you need to get your work done, focus only on your work during those hours, and then leave it behind no matter what. Easier said than done, I know, but absolutely critical if you want to keep your mind in good functioning order. I wrote a few suggestions in this hub:
It's a little bit outdated in that now I'm working on finding that time off around full-time writing AND raising two kids...three kids by the end of the week, since the one I'm pregnant with was due four days ago. Sometimes it seems like more work trying to fit in the relaxation time than it would be to just plow through and do the work, but inevitably, if I give in and just work for hours and hours on end or sacrifice a weekend, I always regret it and end up with a paralyzed mind for a couple of days not long afterward.
As for the editors -- I think some just like to be picky, no matter what. About all we can do is try not to take their suggestions personally, grit teeth and turn in the darn revisions. At least, that's been my experience, I've only told off two editors so far and it's been in a way that they just gently got the message that they were being absurd. For example, I cited a book for my source in an article, and the editor sent back that she couldn't find the link to my source...so I wrote her back explaining the concept of a book. Maybe that all depends on how sensitive your editors are, and just how much it'd hurt you to lose that work :P.