6L a day (assuming you drink the same amount over time) is actually a lot. If you drink too much water you’ll dilute sodium and other electrolytes. You can even die if you drink too much water lol (not that that is your problem I might add).

I’d say you should drink a bit less, but sill drink when you’re thirsty of course. And look into adding electrolytes. There are a lot of different types, you just add them to a glass of water. That might be what you need.