Hang in there mate, you never know what can happen.
I had a family member who was told they had six months; they lived for another seven years and defied every prognosis in that time.
The power of a positive mind is an incredible thing. As others have said, fight with everything you've got and make every moment count. I wish you all the courage and strength in the world, and I hope sharing your story has given you some relief.
All the very best, mate.