Hello! I Have Post Nasal Drip Related To Allergies And

Hello! I have post nasal drip related to allergies and it causes me to cough a lot. I have been tested by an allergist and came full circle with the Claritin I had been taking to begin with. I have mild to moderate allergies and allergens year-round. Problem is Claritin tends to give me a stuffy head and sinus headache. What can I do to help alleviate this issue?