The reality of existential suffering
If we use "existential suffering" as a stand-in for all of the related terms we use, it will help us discuss what we may mean by them. Certainly, distress, dread, angst, anxiety, anguish, or crisis all suggest suffering at least in a mental or psychological sense, a kind of suffering that all people encounter at one point or another in their lives, or even daily. Some existential suffering can be mitigated through changes in circumstances or with the help of others, but when one is dying, whether slowly or rapidly, one may wish to forego the suffering whether or not there may be temporary relief for it.