Sorry but you horrible bastard, no doubt that feline has given you years of affection and YOU chose to have it!!! It didn't damn well choose you. Do the decent thing and take it to the vet asap, you are being extremely cruel already by not having taken it already if it's organs are failing. I took may 18 year old moggy to be put down on xmas eve 2010, worst thing ever but at least I knew I had done the right thing and the last thing he saw was my face not me with a big bastard spade!!!