Slowly losing my soulmate

I've had my little boy Rocky for over 17 years. Recently he developed a tumor on his paw and after testing for surgery they found cancer in his lungs. I am devastated. He is my everything, my best friend my true soul mate. He is only thing I took with me after my divorce. I'm crying myself to sleep I don't want to even wake up to go to work anymore. He is still with me me but he is slowly fading away. I'll miss his kisses and his little sighs. I just don't know how to go on without him, it's like losing a part of myself. I don't know who am I going to become after I lose him. He was the reason I would wake up and go on even when I had the worst days of my life he was the one shiny bright spot in my life. I don't know what do, nothing else seems to be important to me anymore. He is my everything, he is my soul.