To get better, I've been looking for yoga poses to help strengthen my back muscles. The key one for me seems to be the locust pose. It is done by lying face-down and then raising the legs. I did a few half-locust poses tonight (raising only one leg at a time) and it seemed to help. It at least seemed to be exercising the right muscles. I'll give it another go in the morning.
So that's been my life for the last little while. Being sore, resting the sore bits and grumbling silently to myself because, really, I want this better.