I made up my mind that I wouldn't let socks intimidate me. So I cast back on and made it to the same spot I was at last night when it all went to hell. I don't quite know why the stitches seem tighter when I transition from 2 x 2 ribbing to stockinette, but it does. So this time I made a conscious effort not to mess up and to knit a bit looser. So far, so good.
Incidently, neither this sample nor the skein of yarn itself gives a good idea of what the yarn will look like when it's knit up. It looks better than I expected, actually. A stripe of soft green, a stripe of grey and white checks, a stripe of soft orange, a stripeof grey and white checks, a stripe of soft raspberry, etc. Each stripe is about two rows deep. Very attractive.