A Hard Decision To Make

Well I got some devastating news on Sunday. I took my cat Duke to the vet and the initial diagnosis is that he has liver failure. When the doctor told me I just burst into tears!!!! Since I am financially strapped right now I have a very hard decision to make. Do I just let nature take its course or do I have him put down? I am in no position emotionally to make this decision right now. My roommate suggested I sleep on it. Even now as I am typing this tears are rolling down my face.