Try not to be discouraged, several days of acclimatization will probably clear everything up. When I leave sea level in New England and do White and Whitney I land in Las Vegas and stay at the Mt. Charleston Resort (7000') (It cost me $42 dollars a night two weeks ago.) Then a night at Grandview Campground (8000'+), then a night at the gate (11,000') before hiking White. After that maybe another night at the gate or Grandview and then a day or two at Horseshoe (10,000') I find that takes care of it. Although I have used acetazolamide (diamox) in the past I found that I do not need it when taking 4 or 5 days at altitude. Good luck in September.
