This is just my opinion and I am no expert but.... OMG!!! I feel you are drinking "WAY" to much water. This is dangerous and can cause serious heath problems. I did a fast research to see how much we are suppose to drink in a day and it says 2.5 litter per day. They say you can drink a little more than that if it's hot out or if you're perspiring a lot when exercising/working.
I personally normally drink at the very most 2 litres a day and that is calculating the fluids I get from my fruits and veggies, tea/coffee/and the very rare occasion, a soft drink/pop.... I have always been this way.
This is just a personal observation I made and I told my sister about it and she tried it and she was amazed when she tried it.
A few years back I read that we were suppose to drink a lot of water. At that time I was drinking about a litre and a half a day to 2 liters. I was never a big drinker. I was also a little underweight. Always weighted 105lbs since my teen years up to about 45 years old. That's when I started forcing myself to drink more because of what the "experts" say we are suppose to drink 2 1/2 litres a day.
Well from forcing myself to drinking more I noticed I started gaining weight. Then I started thinking....(I'm a thinker. LOL..) I noticed a lot of heavy people always have a drink in their hands. The worst is that it is often diet pop (which I call poison. LOL..). Since it's diet pop they think they can drink as much as they want. And they are thinking that drinking more will make them less hungry so they spend all day drinking. Not Good! It becomes a habit (addiction) of always drinking something. They feel lost if they don't have a drink in their hands and so feel they are missing something and it all started because they were told to drink a lot to loose weight. I call it brain washing to drink more. LOL..
I then stopped forcing myself to drink more and only drank when I was thirsty. If I was hot and/or perspiring a lot from working then I would force myself to drink a little more. When I went back to drinking the way I used to I began to loose weight and went back to my 105 lbs. I tried the test again and forced myself to drink more and I stated gaining weight again!
My sister was as small as I was but in her mid thirties she started gaining a lot of weight and she too just couldn't loose weight and I noticed she too always had a diet drink in her hands. I told her to try this simple test to see if it would work and she agreed.
I told her to throw away "ALL" her drinks, specially her diet soft drinks/pop. I told her to get a container to hold 2 1/2 litres of water. Then try and limit herself from drinking so much by only using the water in this container only to drink and make her teas, coffee, juices. And if she did drink a glass of pop or any other drink or store bought liquid then to go to her container and pour out a glass of water and throw it down the drain. And at the end of the day or the next morning she can then refill the container. This was to show her how much she is suppose to drink in a day and show her she was drinking way too much fluids and that is why she couldn't loose weight.
I was trying to get her out of the habit of drinking so much. I told her of course if she was working in the hot sun digging in her garden and sweating a lot then of course she would have to drink a little more. I told her to try and save enough water so that she can drink 1 glass of water just before eating. "They" say it helps you to not be so hungry and so will eat less if you drink a glass of water just before you eat. So that's at least 3 cups of water from your 2 1/2 litre container.
Anyway, my sister tried to stick to my advise even though she though that it was stupid because she didn't believe you can gain weight from drinking diet pop, water, liquids, but was willing to try anything. Well she was amazed because she did started loosing weight and dropped quiet a few pounds.
So my advice to you would be to cut down on your liquid intake to at least no more than 3 litres a day for a month or so, so that your body gets used to not having so much liquids then work it down to 2/12 litres after that. And if you drink a lot of sweet drinks then you would have to reduce your intake even slower because your body is used to sweets and if you cut out all your sweets then your body will react to that because it would be a shock to your system and that's not good.
Like an alcoholic, they can not just stop drinking cold turkey. It's actually dangerous for them to do so and should see their doctor before quitting. Their bodies is so used to having to process all the sugar that if they stop drinking cold turkey their body could go into shock. They have to drink a lot of sweet drinks like orange juice etc to replace the sugar their body was used to getting in their alcohol drinks. Yes there is a lot of sugar even in beer. Then with time they also have to slowly wean themselves off of their sugar intake.
I did a fast search and here is a link to "Can You Drink Too Much Water?" (The answer is yes)
Anyway, if you try my advice it's at your own risk. I know nothing about your health so don't know how it will affect your body's system. You have to be logical about your water intake and listen to what your body is telling you. If you're really thirty then by all means drink a glass of water but don't drink because of habit.
If you are always overly thirsty to be drinking 4 litres a day then I would advise you to go see your doctor because it could be a sign you are becoming or are diabetic, or a sign of some other heath problems.
Sorry for such a long post.
Please keep us update on how you are doing.