The claritin drug is masking, covering up your allergy to cats, and you may be allergic to other things, like:
wheat, milk, egg, yeast, sugar, corn, rice, fruit (almost all fruit have been sprayed w/ pesticide),
dust (that may be on the cat),
dust mite feces,
skin mite feces,
any hair sprays used,
air fresheners ("Oust"),
dryer sheets, and
you may even have a yeast infection in your sinuses.
One thing that has helped me is a Netti pot (looks like a ceramic oil lamp; you can find them @ Wal-Mart, Akins, Wild Oates, other health food stores; Google it, and find out about it).
Another possible remedy is raw, unpasteurized, local honey (has antibiotics in it, supplied by the bees, to keep the honey from rotting).
This claritin drug is killing your thyroid gland, which controls 43 different processes of the body. Hypothyroidism (low levels of thyroid) can be detected w/ a saliva test(this tests your levels of T3, the vital, and active thyroid).
Do not take the blood test (this will show your levels of T4, the inactive thyroid hormone, which is wrapped up w/ proteins, causing it to be unusable to the body).
To better understand the hypothyroid ism, Google hypothyroidism and Oprah.com, or check out www.doctortalk.com ( the spam-free website for Dr. Howard Hagglund, a naturapath that will properly diagnose hypothyroidism, and your allergies as well.
All the best to you.