I was told I had cancer a week before my twenty first birthday, and given less than a 50% chance of survival. This December, that will have been twenty five years ago. Don't give up. Don't get shaken by whatever odds you get given. Just endure as best you can, and enjoy as much of life in the meantime as you are able.
At the end of the day we all have a ticking clock against us. It's just that most people don't realise it, or think about it, until somebody comes along and shines a light on it. But it is still there, always, for all of us.
Do your treatment, live your life, reach out if you need to talk. That's honestly the best that I can really suggest. Good luck.