I drink 2 gallons a day and more on hot days or on days I work out. "6-8 glasses" of water a day wouldn't even equal 1 gallon and there's no way I could even function on that. My record is 5 gallons of water in one 8 hour period. It was a hot day and I chugged and sweated out an entire Culligan water jug.
Water really can't be the cure all they say it is because my grand parents drank coffee all day and beer all night and they died in their late 70's and 80's. They had to massively dehydrated their whole lives.
If you're chugging water and not eating much it sounds like your on that diet that Andy told us about a while ago- the warrior diet. I've been doing that for a while and it's kinda like taking the red matrix pill, you can't go back.