Basically, you went *splat* on the hill. The idea is to stop just before you hit the nausea point. Then try the same hill on another ride. And another. Keep doing it, and eventually your circulatory system will develop the strength to handle such a steep hill. Your body *will* get the message from just trying once or twice a week.

Pushing to the nausea point means there's good odds of you not thinking straight. Even if it's fine for your body in the abstract, it's a silly thing to do on a road. Bad judgment leads to accidents, whether it comes from alcohol or oxygen deprivation.