Breast MRI tomorrow, bad allergies and congestion!

I am miserable with the tree pollen, I'm taking an antihistamine, steroid nasal spray and a sinus rinse, still can't breathe well through my nose. I called the breast surgeon to see if I can put this off until I'm breathing better in a few weeks and she said I'm high enough risk that she wants me to "try" tomorrow. Ugh ugh ugh. Is there any hope of keeping my head somewhat elevated? I'm just not having a good feeling about this at all. ((