How to stay away of fear from death?

I think you are just experiencing a aspect of life!!. Death is a bitter part of life. I dont think this is a disorder because it is human tendency or state that we get affected. Everyone goes through the trauma some time or the other as he sees death of their near and dear ones. This could be natural or accidental. Even in case of natural death, till the time person is declared dead he was alive and so you would still believe he would have lived another few years. So it does not matter on the type of the situation, the mindset is similar. I feel that you have touched the softer area of human mind and it is same with everyone. So dont think it is a disorder. It is natural reaction to the event.