Well, several days have passed and I'm starting to feel a lot better. Have had appointments both with physio and chiro. Fingers crossed (really, really crossed), I'm hoping to make a gradual return starting on Sunday. Assuming I'm totally pain free for the required number of days prior to that, of course...
Based on the good advice above, the keys things are going to be:
Improving technique - straight arms, stay squished up in a ball for longer, avoid standing so quickly
Grip the handle both palms down on the start
Shorts with reduced drag!
We'll see what happens...