My cat has been off her food for a few days now but not showing any visible signs of illness until this afternoon when I found her crashed out on my son's bed. I noticed her shivering and that she has quite a large soft lump under her chin. She's only 16 months old so I assume not a tooth problem but could it be an abscess? We can't see vet until tomorrow eve and am worried - is there anything I can do to help her before she's seen? I know cats are usually really poorly before it's obvious :-(