I'm guessing that if you get to the point where you alternate between crying and cussing out your co-author in absentia, it's probably time to put the paper rewrite away and go home.

I don't know. I may just flush this project. It seems like every time I send it to my co-author, I get back a badly-chopped-up paper full of not-very-helpful suggestions. ("Fix this" doesn't give me enough direction. I'm not a mindreader.)

I'm just not feeling well today, either. Female stuff. As much as I dread the thought of hitting an age where osteoporosis could really set in, and where I start having to worry about things like colonoscopies, I'll sure be glad when the every-couple-months surprise anxiety-fest goes away.