You have done fine on Dana (13K) and had trouble at Trail Camp (only 12K). Possibly the excitement and lack of sleep contributed to your troubles. I would consider starting later.
Altitude sickness tends to show up when people are resting and especially if they are sleeping. This is because an un-acclimatized person doesn't breathe enough while resting at altitude.
Ken isn't the first person I've heard recommending a 10-minute break every hour. I just don't buy it. It is better to go slower but KEEP MOVING. Yes, you should stop frequently for a byte or two of food. Drink, pee, and take pictures as often as you like. But don't spend one sixth of the day sitting on your butt letting your legs stiffen up and your breathing slow down until you get AMS again. The tortoise beats the hare every time.
Diamox may help. Remember that the correct dosage of any medication is the smallest does that is effective. 250mg is the most common tablet, but I don't think anybody needs that much for AMS. It's common to take it for a few days before going to altitude, but half a tablet when you start up will probably get you to the summit and back down low enough that you won't need any more.
The more time you can spend at 8K - 12K before you head up Whitney, the better. Moderate exercise at altitude is key.
Good luck!
