Awhile ago I had a thought relevant to this. I was thinking about the experience of death (that is, the cessation of the aggregates/running under the assumption of no post-mortem rebirth) and I realized I had the tendency to imagine that after everything else had ceased, that there would be something of the mind remaining to perceive the lack of experience, like being shut in a dark room with no way out. This lack of experience is what primarily is scary about death, I think, separation from this world that we're so attached to.
I realized that this was a completely flawed way to think about it, since the mind is not some constantly conscious separate observer apart from everything else. The coming and going of sight, hearing, smell and the rest are all not too difficult to understand, the physical sense bases are dependent upon the body, and with the meeting of these and "external" objects there is consciousness/viññāṇa and contact/phassa, which comes and goes as objects and attention change and shift, there is nothing constant about it. But the origination of what we might call the mental-base for mind-contact is not as obvious, or, wasn't for me. By not understanding the origination of the mind I had been falling into assuming something constant there.
But I realized that I've never had any mental experiences or occurrences of mind-contact that were not based on the raw material of previous experiences, contacts, of the other 5 senses of this same body. Feeling/vedanā and perception/saññā arise due to previous conditioning of past experience, dependent upon either new experiences as they come and go or on old material "recycled" by the mind, and all of that is the material that memory, imagination, association, and all those other mental processes work with.
Which means, that there is no reason to assume that this mind and all of it's wriggling are based upon anything but this body (just talking experientially, nothing metaphysical intended), and no reason to assume that something of the mind could remain when everything else has stopped. There would be no piece of the mind trapped there to be tortured by nothingness, nothing remaining to perceive the lack of experience. No consciousness or any other mental process could remain. And so, no cause for distress at all.
It would, in fact, be the most complete peace possible. No possibility of an ounce of dukkha in any form, ever. In this way I think I now understand how it is that parinibbāṇa, the ending of the aggregates, is not something to be feared. I've had some tension about that in the past, based upon that same old unanalyzed delusion of mental constancy, that there is some "thing" to be separated from the world.
I'm not saying we should kill ourselves, just that when you really think about it, there is no grounds for fear of death as we usually tend to think of it.