Look. No-one wants to die. I am like you, and I don't like to think of death. Death scares me as much as it scares you. Everyone has mini freak-outs, and anyone who says they don't is a freakin' liar. I have had a lot of death in my family, and so has my mum. Her mum (my late grandmother) died when my mum was about 20. In the last few years I have had several people close to me die. I am terrified that my mum will be taken before her time.
If I have a mini freak-out, then I have a little sort of routine. It normally works, especially with social and emotional problems. I get into a quiet room, either our spare bedroom or my room, turn off the lights, and get into bed. I cover myself fully with the duvet, curl up and close my eyes. I think of that little space as My Space. I tell myself (out loud, it helps to say it) that nothing bad will happen to my in My Space, because it is mine and no-one else's. Once I am comfortable with My Space, I stretch out, thus extending My Space. continue to tell myself that this is My Space, and nothing can hurt me here. After I am happy and calm with that I poke my head out on to my pillow. I continue extending My Space until it covers the whole room. This can take as little or as long as you want, as long as you are calm and happy at each extension. After this, I have normally calmed down and am ready to face the outside world.
Try this if you have another mini freak-out. It helps me a lot. And just think. Are the people you love going to think of you as a rotting corpse in the ground, or remember you as the smiling, happy person you once were?
I have great respect for you. It takes guts to talk about your fears, even in this way.
Good Luck.