Is it possible not to eat and just drink whey protein 3x a day....

or probably 6x a day.

Hmmm... your question is confusing. Could you elaborate?

IMHO whey is a last choice -- not a first choice.

For example, if you are going somewhere and you are afraid that there will not be any low carb food -- then pack some low carb shakes / bars / powders.

Or if you are on the go and can not get a prepared meal (most low carb meals require some preparation) then a whey bar / shake might be appropriate.

Yes, it's possible, in the sense that it would be somewhat superior to, say, outright starvation. It's beyond me why anybody would do that voluntarily when there are so many incredibly delicious and satisfying whole food sources of protein readily available.

You would also need to take laxatives as an all protein powder diet would make you very constipated.

Frankly, getting enough protein is the least of my worries - I'm struggling to cut back on it. I noticed yesterday that there are a few little bubbles in my urine. I can't recall if it's been like that before, but it's got me scared as hell.

Whey protein is just that. Protein.

You also need vitamins, mineral, and fats to be healthy.

Very bad plan.