Like Red, I wonder if your bike is okay. If your brakes are off center, you might just be fighting your bike.

But as for the congestion: I suffer from year-long allergies. For as sneezy and stuffy as I often get, I can usually take full breaths from my lungs. The congestion is mostly in my sinuses, with some mild drainage down my throat. Once there's congestion in my chest and/or thick drainage, it's usually because I have an upper respiratory or sinus infection. In any event, breathing difficulty is not something I'd pass off as just seasonal allergies--at least not without talking to a doc first.

I will say that my allergies of late have been awful. I'll have a good few days and then, bam, I'll spend a day sneezing, blowing my nose constantly and generally feeling pretty rotten. Saturday was one of my bad days. I took an extra half-dose of Allergy finally and was fine the rest of the weekend.