Pug-
Sorry to hear you're having to deal with the extreme shifting. It sucks rocks.

Didn't you start meds fairly recently? I've found it takes up to several weeks for meds to level out my moods and keep me from ping-ponging back and forth.

I'm too lazy to do it, but my docs and some fellow bipolars have encouraged me to maintain a mood chart. When I do manage to keep track for awhile, I find that the simple act of filling out and reviewing the chart each day/week levels me out a bit. It's as though the shifts take on a less drastically contrasting feeling just from seeing it all down on paper. Plus, it forces me to quantify the mood extremes and I get a better feel for just how far out of balance I really am.

When I'm feeling particularly shifty I try to avoid the rest of the world to save them from me - so I read to distract myself from the moods. I see you're doing a lot of reading lately. I'd try sitting down (under the tree perhaps) for a read whenever you get blind sided by a mood change.

Keep trying to head for the center, and good luck.