Just got back from the ER for dehydration.

I've been drinking a gallon of water everyday during my waking hours plus juice and ice tea. I also get up 3-4 times a night to drink more, as I actually wake up due to thirst.
Still for about a week no matter what I do, I am so thirsty it's like I haven't drank in a week. I'm also not going to the bathroom anymore than normal. Saw an OB, not mine, last Tuesday, he simply said increase fluids.
Then the dizzy started today, I was very dizzy and out of it.
According to the ER doctor this is normal, both the being so thirsty and the dizzy.
So I need ideas to stay hydrated or even better that work better than what I'm doing now. I got some gatorade to see if it helps.
Thanks a bunch.