Thanks for all the posts, DMs, and texts. I didn't want to say anything till I had all the results back. I've a burst fracture of my L1 vertebrae but nothing else seems damaged. Some bits of bone went outwards, some bits went inwards towards the nerves. Very fortunately there isn't any neurological damage. The fracture is stable under gravity so I can stand up and move around and have now been discharged from hospital.
So it looks like limestone season is a bust this year, but considering I've shared wards with people who have not sat up or been out of bed in two years, and have no use of their body beyond their hands, I'm pretty sanguine about it all.