Is there any thing stronger for allergy then 180 mg fexofenadine? Once that stops being effective

See your doctor. Fexofenadine and other antihistamines can help control the itching and sneezing associated with allergies, but do not work well on the congestion or other symptoms. If you have symptoms that cannot be controlled with fexofenadine, see an allergist or at least your primary care doctor. They may be able to help find the cause of the allergies and/or better medications for your symptoms.