All of these issues are temporary growing pains along the pathway to living Happy, Thin, and Free.
Fogginess can be due to the early stages of detox and withdrawal.
One of the benefits of Bright Line Eating, after a while, is a profound mental clarity. Mental states generally do get better and clear up as time passes.
For dehydration, consult your doctor. Drink plenty of water.
If you think you need more salt, check with your doctor, but, so long as you don’t have hypertension, I think it’s okay to salt your food. Salt affects everyone differently. Some people retain it, for others it passes through. You may end up finding you need to add salt to your food on this plan, since you’re most likely eating less processed food (where salt is already incorporated).