My nosebleed stopped at 8am. 6 hours of heavy bleeding and no sleep.
The doctor visit went well. It's bronchitis, and she reckons that this contributed to the heavy nosebleed.
She gave me antibiotics and a puffer/inhaler. So far., so good, so I puffed and inhaled, took two pills ... and then the nose started to gush again after I sneezed. Bah.
... later ...
I managed to cap the gusher after about an hour.