One of the things that reportedly tends to happen in your sort of case KC is that having created something we fear (e.g. the thought that we might die) we start to push it away from us (we suppress what we fear), and to as a result of our fear pump energy into it.
As Blink said 'with our minds we create our (the) world'.
This makes it grow as a separate entity within our mind ( a bit like schizo tendencies), and the loss of energy can come to make us feel very down too. It reportedly becomes a vicious circle in that the more energy we pump in the greater the fear becomes the more it frightens us the more it sucks our energy the more.... ad infinitum.
As ever stopping the flight (finding the courage to move towards and rest in the fear until we can with luck and work come to see that it's in truth just a delusional construction) and extending love in place of the hostility seem to be the answer - until we do this we keep on giving it existence as a growing 'demon' (not Hollywood style) or a separated part of mind.
I posted before about the Tibetan Buddhist practice of Chod which is designed specifically to deal with this sort of problem by this means. This book by an American nun named Tsultrin Allione sets it out in more detail:
http://books.google.ie/books?id=yJEUIQAACAAJ&dq=inauthor:Tsultrim+inauthor:Allio...She also has a CD out there on the topic named Cutting Through Fear which is pretty widely available (it showed up in our local bookshop):
http://www.namsebangdzo.com/Cutting_through_Fear_Tsultrim_Allione_p/11729.htmAnother Buddhist nun Pema Chodron has written on the subject of dealing with fear too, this time by slightly different means:
http://www.amazon.com/Places-That-Scare-You-Fearlessness/dp/1570624097She presents a more comprehensively argued view if you are of a thinking inclination.
Both in my experience set out very effective practices, although the effectiveness is probably linked to developing a degree of meditative skill. (my experience was in dealing with fear and a sense of failure when ill, my path was via meditation and not unlike Blink's) I found Buddhist and other spiritual perspectives on the nature of existence very helpful too - they in very logical terms tend to point out that while death is a change of state we can't die.
The guys have already mentioned how 'non-ordinary' experience can help, although that too for most of us requires work and practice to access as well. Bruce Moen's books are not a bad place to start, and are a lot more accessible than more traditional approaches:
http://www.amazon.com/Afterlife-Knowledge-Guidebook-Retrieval-Exploration/dp/157...One caveat is probably as implied above. Viewed using more 'scientific' language this sort of fear is presumably the result of a view or conclusion having been imprinted in our mind - usually at an early age when we couldn't see past it, and usually at a deep level we don't have access to in normal consciousness.
Meditation is one way of accessing the required levels, but depending on the state of your mind it usually takes quite a bit of time and practice. Stuff like the Monroe Institute's Hemi Sync tapes, holotropic breathwork and even the likes of Brandon Bay's 'Journey' CD are probably worth exploring as ways to help speed up the process too.
This most definitely is not a recommendation, but various 'substances' like marijuana and other stronger agents (it's reputed) if used correctly can facilitate the required access too, with the selection of agent depending on the levels at which you are carrying the issue.
These things can also be (slowly) nibbled away at from normal levels of consciousness its seems too - by making quite explicit exactly what it is that we fear, and using logic, research, psychotherapy, experience (perhaps non-ordinary experience as reported by guys here) or whatever to overturn the old logic.
There's (without a lot of luck) no instant answers, but there are lots of ways and means. It starts with turning inwards and beginning the journey of self discovery. Most of us started from one or other position of personal crisis......