Not even Gatorade is getting a pass -- small sips of ice water are all that stay in. That means it's doctor time.
Broke down sobbing when I realized this -- feeling very alone, useless, powerless. Ironically, that cheered me up immensely: One of the symptoms of severe dehydration is inability to produce tears while crying. So, as long as I can cry, I'm not dead yet.
Will report back in after the professionals patch me up.