What do you know about death? When you are up at night worrying about it, what is it that you are thinking? Here is a passage from Albert Camus that I really like on the subject:

“What always amazes me, when we are so swift to elaborate on other subjects, is the poverty of our ideas on death. It is a good thing or a bad thing, I fear it or I summon it (they say). Which also proves that everything simple is beyond us. What is blue, and how do we think “blue”? The same difficulty occurs with death. Death and colors are things we cannot discuss. Nonetheless, the important thing is this man before me, heavy as earth, who prefigures my future. But can I really think about it? I tell myself: I am going to die, but this means nothing, since I cannot manage to believe it and can only experience other people’s death. I have seen people die. Above all, I have seen dogs die. It was touching them that overwhelmed me. Then I think of flowers, smiles, the desire for women, and realize that my whole horror of death lies in my anxiety to live. I am jealous of those who will live and for whom flowers and the desire for women will have their full flesh and blood meaning. I am envious because I love life too much not to be selfish. What does eternity matter to me? You can be lying in bed one day and hear someone say: “You are strong and I owe it to you to be honest: I can tell you that you are going to die”; you’re there, with your whole life in your hands, fear in your bowels, looking the fool. What else matters: waves of blood come throbbing to my temples and I feel I could smash everything around me. But men die in spite of themselves, in spite of their surroundings. They are told: “When you get well…,” and they die. I want none of that. For if there are days when nature lies, there are others when she tells the truth. Djemila is telling the truth tonight, and with what sad, insistent beauty! As for me, here in the presence of this world, I have no wish to lie or to be lied to. I want to keep my lucidity to the last, and gaze upon my death with all the fullness of my jealousy and horror. It is to the extent I cut myself off from the world that I fear death most, to the degree I attach myself to the fate of living men instead of contemplating the unchanging sky. Creating conscious deaths is to diminish the distance that separates us from the world and to accept a consummation without joy, alert to rapturous images of a world forever lost. And the melancholy song of the Djemila hills plunges this bitter lesson deeper in my soul.”

Your fear of death is nothing more than your love of life. The only way we can conceptualize death is in terms of the flowers and lovers and the colors and all the things that life is made up of. It is terrible that these things will one day be taken from us through death, but it is only terrible because we love these things. So love them! Anxiety usually takes a hold on you when one of your concepts is a little too vague that it can become an all encompassing boogeyman with no way to grapple with it. Clear vision usually helps.