What Causes Tiredness And Sinus Headache Inspite Of Being On Allegra D?

Hi! I have really bad allergies but have seen an allergist before and I m not allergic to anything. He told me to stick with Allegra D but that hasn t done anything for me. I do everything natural (steam, nasal rinse) but everyday I feel tired, my eyes feel heavy, bad sinus headache and dryness under my eyes with rashes. I feel this all due to seasonal allergies but nothing is working and i need relief. Any suggestions on what to do or what kind of doctor i should see?