When the time comes you will find the strength you need, whether that is to keep on going and face living with all of its pain and glory, or to go out on your own terms. Either way you have to believe in yourself. When you are that much alone yourself is all you have. If you can believe in anything believe in your strength to do what's best for you, whatever that choice may be. The human mind's capacity to experience pain and suffering and to withstand it is equally great. You'll know what's right for you when it comes down to ultimate endings.