how do you overcome the fear of illness & death

One breathe at a time. One day at a time.
Experiences go up and down. Look at the beautiful things. This will keep your spirit young. The trees, flowers, children, make new friends..help..
Look at how nature dies. Yes death energy is terrifying.... Let's accept that. It is, very scary, all devouring. Yet too, cleansing, transcendental, liberating.
Look at an ending of anything. Endings in relationships or life cycle's. Every loss is followed by a field of void, and chaos from which sprout the New.
It's the biggest mystery, where we're going and I think it's only valid to have feelings of awe and excitement. Let fear guide you, let fear show you, do not be afraid of fear.