That cheered me up so much that I turned around and rode back home again, doing 17km in 50 minutes, an average of just over 20km/hr. It's been great for my morale, and now I realise that there's a good chance that I can bike to work later this coming week. I'll do three or four more build-up rides of 6-8km and I should be OK to try a work trip by Wednesday. The ride home into the easterly will be bad, but I'll tackle it the usual way, by dropping my speed and taking my time.
Later: I had most of dinner prepared (fillet steak with onions & mushrooms, boiled potatoes, asparagus, salad of onion/cucumber/capsicum with parmesan and herbs) when I received a summons to appear at my local. Right, I thought, time for another bike ride, and I did a 6km ride to the pub, 20 mins each way. Back at 6.30pm to cook dinner, now relaxing after a nice meal and a couple of glasses of merlot.