When you are facing something like this, you have to KNOW you won't lose. You aren't just a number or random statistic. .. at least, you aren't if you have the ability to believe in yourself.
The mind is EXTREMELY powerful in affecting our health and life. There are many many studies which show the very real effect the mind has. Did you know elderly die of old age more often AFTER an important event that they are looking forward to? Their wanting to see a wedding of their grandchild, or celebrate a birthday, or whatever other event is able to keep them alive. Or, the link between older couples where one dies soon after the other is killed (having given up living because of the loss of their partner).
If you know you will beat it, you give yourself a MUCH better chance of doing it. This is true in every aspect of life. ..from those who reach the gold in Olympics to those who learn to walk when statistically it is "impossible". Everyone who has overcome hardship are those who have not given up.
Do you want to live? Do you have things you still want to do? Then don't give up. Go at it like no one has before. Watch what you eat, exercise, get lots of sleep, have the doctors do the things they think will help .. doing these things is unusual, doing these things makes you outside of the norm, doing these things makes you part of that group that gets past it and lives a long life.
If you roll over and just give up on life, you will die. Giving up is just feeding your condition and letting your body fail. ..instead of using the power of the mind to help you, you are using it to guarantee your failure.
So, don't give up.. .you have already been through a lot in life, this is just one more bump in the road you will overcome.