About 30% of the population suffers from nausea after anesthesia. (I'm among that 30%.) In the future, you can let doctors know anesthesia nauseates you, and they will try to mitigate it (with anti-nausea meds).

If you are testing gravity, you might want to wear your helmet (!) when you're on your feet until you're stable, just in case.

I hope you are starting to feel better! And yay for getting your knee fixed!!