You're not alone. My allergies get really bad sometimes too. One method of dealing with strong allergic reactions is to stop them before they start. Not by taking anything, because that usually has side effects that are almost worse! I'm suggesting you try an ages old method of sinus irrigation rapidly finding new users. It's called "neti" in Sanskrit, but most folks just call it relief. By gently irrigating the sinuses, you can literally flush out much of the allergens that cause reaction.
In our office, my staff and I personally use (and yes, sell) SaltAire Sinus and Allergy Relief. It's sold in an easy to use bottle with complete instructions inside. The procedure is very easy to do, and has brought real relief to myself and many of our patients with regular use during the worst of allergy seasons.