New Year's Day, sick dog!

I'm starting the year with our beloved dog sick, lethargic, not eating but still drinking, and with a large swelling in her neck.

I KNOW THE WORST CASE SCENARIO, so please don't mention that, but anything about relieving inflammation or suffering in a 60 pound dog, about 5 years old, is welcome tips. Right now, I would rather not stress her with the expense and stress of an emergency vet until tomorrow morning when her usual vet will be open. She's got anxiety and I would prefer resting comfortably to panicking about strangers for her.

Edited To Add: She's going to be okay, probably. :-) Vet says most likely an allergic reaction, Prednisone and Benadryl for a week. Thank anything that watches out for beloved animal companions! 💕 🐶🦊🐺