My cat Problems are unidentifiable!! Please help....?

Maybe your cat has had a stroke. One of my kitties had a stroke and couldn't walk well, lost control of both bowel and kidney function. It could be the heart ,or internal bleeding .You say your cats' body temp. has changed, this is a sign of heart or internal bleeding.. He may be dying as the vet had told you...Get a second opinion if you are not sure . If your cat is dying, ask the vet for something to keep the cat comfortable until it passes..I know it's hard (been there, done that). just please, DON'T let your cat suffer. Good Luck!