my heart is a glorious machine;

It's one of those days where I can't soothe myself -- I'm jumpy and panicky and close to nauseated for no apparent reason and can't concentrate. Usually this means I spent most of the day faffing around and making myself feel worse. I wouldn't say that this sort of thing happens all the time, but it happens frequently enough that I need to find a coping stratagem. So... how do you calm yourself? Especially when you're jittery and uncomfortable purely as the result of chemicals doing silly things in your head? Trying to work on something productive but low-stress, like reading some of my more interesting research books, maybe working on icons or photography, organising thoughts and/or inspiration on the Novel if I'm not in a state to actually write, tends to alleviate the urgent sense of guilt (yep, I get purely chemical guilt, too, in addition to the guilt-as-default-response I already deal with! fun stuff), but that's not much use if I can't make myself concentrate on it. Sometimes eating helps, because when I'm depressed or have a cold my eating schedule goes way off balance, but that's usually just because some of the nausea or jitters are from not having eaten properly. I have a relaxing Lush bath bomb from barefoottomboy that, um, I still haven't used, cos when I use it, it will be gone, but it's lavender-scented and if I crumble a wee bit off it's rather soothing. Actually, if I just unwrap it and inhale, it's pretty gorram soothing. (When I have money again: purchase more Lush products. This is not frivolity.) 

So I'm setting down to read London: A Biography and trying to take deep breaths, but I know this isn't going to do half as much as I'd like. Any suggestions, for now and for the future?