I suffer from severe panic disorder brought on by fear of death and dying, so I know exactly how you feel. I find it helpful going to spiritualist churches and visiting mediums, as silly as it sounds, it really puts my mind at rest that there is something beyond this life. Have you tried any of those things??
Part of my panic disorder leaves me thinking that I am the only one who feels this way about death, but its good to know that I am not the only one, and that people like us could support eachother.