I have now been on LC for 2 months and I am happy with the weight loss. The thing I am not happy with is the fact that I can no longer hold vast amounts of liquid.
I used to be able to drink 8 glasses of water a day and only need to go to the bathroom once a day. Never had to get up at night either.
Since I have been on the diet, I feel like a tap without a shut off. Is this a common thing?

It's common and it's healthy. Usually water retention and lack of elimination is caused by sensitivities/allergies. A common food allergy is wheat, i.e. breads. Atkins removes this allergen from the diet. Result..less bloat/many bathroom trips.

Another thing...Elimination is the body's way of getting rid of wastes and toxins. More water, more bathroom trips = less toxins = clearer skin.