In my inexperience, I would have swung the aircraft around and vacated the runway back onto the taxiway, provided no-one else had come up to the hold. Would that have been an option?
Possibly. I'm afraid I didn't think of it until afterwards. Vacating back the way I've come after entering a runway is something I've never ever done before, so it's not something in my toolbox.
(It wasn't a desperately wide taxiway and might only have worked quickly enough if I'd been to one side of it, rather than in the centre where I actually was.)