Funny, I am now going through almost exactly the same situation. Quit drinking 3 weeks ago and have been super thirsty. I probably do about 1-1.5 gallons per day, sometimes less but always try to drink some water for a few hours before I go to bed. One big nice pee then it's lala time. Wake up thirsty as hell, take another nice pee and get some water in me. Eyes are mohave dry, mouth is almost leather it's so dry sometimes and my near vision is toast for a few hours. My glucose levels have been fine, no weird values but not 'offical' from the doctor, just my own monitoring. I was worried I had diabetes. I am pretty much chalking it up to the major carb & general metabolism makeover. I was averaging about 35 drinks per week, lots of that was high quality beer. My guess is all the weak ligaments, injuries and such will go away in about 6-8 weeks like it did last time I quit drinking. Worry not my friend (but have a doc look at you anyway.) Quitting drinking (for good this time) will probably prove to be THE best decision I've ever made. I already feel great and don't miss it AT ALL. Good luck!
You should never exceed 100 ounces of water a day. 2 gallons=256 ounces.
Drinking to much water or "water intoxication" causes the other nutrients in the body to become diluted to the point that they can no longer do their jobs. This causes an electrolyte (salt ion) imbalance.
Symptoms of water intoxication actually look a lot like the symptoms of alcohol intoxication, including nausea, altered mental state, and vomiting. Also headaches, muscles weakness and convulsions. In severe cases, coma and death.
Your high water consumption can be from anxiety or because of a physical reason. You need to immediately see a doctor, tell him of your situation, including the alcohol, and get a complete blood workup. And of course get your blood pressure checked. I am not a doctor but I would suggest you stop at the nearest 7-11 store and get a gatorade on your way to the doctor's office.
If you just quit drinking you are going to have to give your body time to adjust.
abby