I am so sorry that Tiger is obviously at his closing act of life. All you can do at this point is love him, love him, love him and provide him a quiet and peaceful environment. I've had 7 cats in the last 50 years and it was never easy to see the end coming and to experience the loss of my beloved cats. Some died from that old nemesis kidney failure. One died from some sort of bone cancer like a leukemia. My last loss was my Maine Coon Bijou, who curled up at my side on the couch a month shy of her 12th birthday and just never woke up.
When it's Tiger's time, he will let you know, and you can then help ease him out of his pain of this life and onto the Rainbow Bridge. Again, I weep for you.