Your symptoms suggest an allergic or viral response causing acute coryza (inflammation of the nasal lining), which may worsen in the evening due to environmental changes or a drop in temperature. Watery nasal discharge along with increased salivation may occur due to irritants or allergic rhinitis (hay fever) and is often more noticeable when lying down or in the evening. Using a non-drowsy antihistamine and keeping your bedroom free of dust and allergens may help reduce symptoms. If your symptoms persist or become severe, it is advisable to consult a doctor for further evaluation.