Stronger prescription antihistamines?

Am exactly like you. My allergies to dust and dust mite are way too much for any antihistamines to handle. Now am pursuing other treatments that can lower my allergies, which include immunotherpy and herbal medicine. It is a slow process but hopefully one day i won't have so much allergies. My best advice for you is try to lower your allergies instead of just trying to cure the symptoms which is what the antihistamines do. Since you are mostly allergic to dust it would be good to try herbal medicine and immunotherpy would not be so bad either.