That seems like a pretty appropriate feeling, since full astral projection does mimic the death process. (Death could be seen simply as a final and permanent astral projection.)

Getting 'close to death' is indeed a major part of spiritual training in many traditions and different ways, from the yogic and Taoist aspect of stopping breath and heart rate to the shamanic experiences of torture and starvation.

One way to look at the reason for this is that the ego is essentially bound up with survival and with avoiding fearful situations which might lead to death. From that point of view death can only be a good thing, since it does nothing but lead to growth. Taking this too literally would be not only unfortunate but verging on the psychopathic, however the fact remains that brushes with death often lead to spiritual experiences -- read Kason's "Farther Shores" where she anatomizes this very well, having had such an experience herself and studied those of others at great length.

Certainly fear of exit from the body, which Robert Bruce writes about at length in his classic "Astral Dynamics", is definitely caused by the animal fear of death. One way or another fear is the problem, so one has to learn to ride the dragon.