I gather 1 US ounce is 29.57ml, so 139 ounces is about 4.1 litres a day.

That sounds like a lot to me. I drink about 1.5 litres a day. None of that is water; it's either coffee, milk or a blackcurrent drink.

I do wonder whether you are, indeed, addicted to tea and coke and whether it's the addiction which is causing you to drink so much. Which isn't to say tea or coke are not good sources of water, just that they may be causing you to drink more than you need.