Ouch. Was it altitude sickness or something else (flu, diarrhea, food poisoning, etc.)? If it was altitude sickness, how much acclimation did you have before hiking up?
I don't know if it was AMS or not, but odds are it was. I felt sick to my stomach and had a slight headache.
I acclimated by climbing all the local mountains (Jacinto, Baldy, Gorgonio, San Bernardino) for the few months before my hike. No issues on any of those mountains.
I went up to Horseshoe Meadow campground to hike around for a while the day before. I slept at the Portal campground the night before.
I think if I would have stopped to camp at Outpost Camp instead of Trail Camp it might have helped more.
I have heard that AMS can hit anyone at anytime so you just have to prepare the best you can, but understand that, sometimes, you may need to turn around and try again another day.
