My mom was 51 when she died of lung cancer. Doctors gave her 3 years, she made it to 5. Wasn't a smoker, drinker, unhealthy, etc. Sometimes shit happens.
But the one thing I did learn from her, is to always live your life and never take a day off.
It has been 29 years she passed and I still run into people today who tell me how much they remember her as well as miss her. The best compliments I get is when people tell me that I remind them of her.
Don't ever give up. Whatever is on your life's list, do it and don't question it.