It is very likely you suffer from house dust mite allergy
and will need either blood tests or specific IgE tests to confirm this. Other aeroallergens such as moulds, animal dander (if you have pets) should also be checked.
You need a combination of long-acting antihistamines such as Fexofenadine
180mg in the morning, mometasone furoate nasal spray
1 spray per nostril once daily, Montelukast
10mg at night for the winter months (3 months) to see the benefit.
Obviously the best decision on duration & time of treatment will be decided as per the results.