I'm not an expert with that subject, because nobody is able to answer this question properly.

I think you are afraid about the meaning of life. Some people figured it out by adopting a religion, which most of the time offer a mission, a goal to achieve. In this sense, death appears to be pretty harmless. But guys like you and me can't solve this problem because ANYBODY has the truth about this. The fear of the unknown is frightening.

My advice is that you can't decide when you will die. Your only field of action is the way you live at this moment. Where are you going to (regarding your life's goals)?

Good luck!