The last 45 minutes have been intense. I believe the source of all of Annabelle's congestion is the dry heat in the apartment from the radiators. This morning, she was completely congested, so I dragged her into the bathroom, wiped her nose to see if there were any dried gunk blocking her nostrils, then flushed her nose with several syringes of water. She fought a lot, so here's a tip:
Never Ever dose a cat wearing only your underwear; wear armor.