Is there always saliva in your mouth? even if it feels dry?

Yes: No one is totally without saliva. In your age group, unless you are on certain drugs or have certain medical conditions, your decrease in saliva is likely due to insufficient hydration. Drink plenty of water.

Dry mouth: Saliva is rich in antibodies and enzymes that are important for your oral health. Saliva also serves a buffer, keeping your oral ph as healthy as possible. Most likely you still have saliva in your mouth even when it feels dry. But why does it feels dry? Some drugs, medications and medical conditions can result in dry mouth. If this is a common occurance you should see your dentist.

Yes: But your salivary output can be affected by drugs, amount of water intake, diet, etc.