Eve, I also usually get my Hay Fever right around Aug 25th (my husband thinks I’m nuts for pin-pointing it to a DATE, but that is how it is!)
I’ve had bad allergy problems since I was in grade school. I’ve learned a few things. Maybe I have one or two tricks you haven’t tried yet!!
I develope an immunity to allergy meds in around 1 pack. haha So as soon as I finish with one pack of medicine, I switch to another type.
I ALWAYS take a Benadryl before I go to bed (during my allergy season, of course). If I wake up in the middle of the night, I take another one so that I don’t wake up with the gunk eye. (that’s what we call it at my house, anyway). If I don’t do this for the night, I rub my eyes in my sleep and wake up with itchy, itchy, itchy red gunk eye.
I don’t even BUY Visene. To my knowledge, the only thing IT does is make my eyes a little more presentable to other people. Visene never makes my eyes feel any better, or itch any less. It just takes SOME of the red out.
When allergy meds don’t seem to be working, I switch to taking Day Quill. It’s cold medicine, but it works wonders. Dimatap is also wonderful for allergies, but it WILL make you tired.
ummmm, besides that you have probably tried the other stuff I do.
God Bless you again, and good luck taming the Hay Fever. Trust me, I FEEL YOUR PAIN! 
Oh yeah, and Clariton has never done A THING for me either. It’s useless as far as I’m concerned. I actually don’t even bother going to the doctor any more, because they have yet to prescribe me something that works.