Dear Tumblr: Allergies

I am suffering mightily from what I believe to be seasonal allergies:

• My eyes water.
• My sinuses feel like hollow caverns attempting to burst, like a bubble in baking bread, from beneath my face.
• My nose runs.
• My throat is sore when I swallow.
• My brain is running at about 60% capacity.

I took a Claratin at about 4:00 this morning, which I guess took some of the edge off, but I think it may have contributed mightily to my perceived lowered cognitive abilities. In short: do you suffer from similar afflictions? What do you do, and what can you suggest I do, to cure these ills?