To my way of thinking, there are four levels of consciousness. Awake, asleep, unconscious, and dead. When you 'are awake, all of your senses are active. When you are asleep, they are still partially running in the background, ready to alert you to danger. You get to dream too, if you are lucky. We've all experienced that. Unconscious, I have experienced this year, both as medically induced [several times], and as a result of severe illness [twice]. In both situations, time has stood still, very still, and all senses have been muted. The Pain went away, the passage of time went away. One minute I was there, and over periods of up to two days, time stood still. I simply woke as if from a very drunk sleep, with a strong urge to be left to adjust quietly. My perspective of unconsciousness is a near total shut down of the senses and all but essential muscles and brain functions shut down. I experienced nothing for two days. Without massive medical attention I would never have woken up. There's no evidence to support any theories that it was anything other than scientific expertise and strong medications that kept me alive until the crisis had lessened. If I hadn't woken up, I would have continued to feel nothing, I would continue to be unaware of the passage of time, and eventually I would die of lung failure, heart failure, or kidney failure. without clean blood taking oxygen to the brain, the brain dies. You cease to be a sentient being, and turn into an inconvenient lump of flesh and relaxed muscle. All while feeling nothing, doing nothing, remembering nothing.
Death is the onset of nothing. A measure of time such as eternity is meaningless, because your brain's clock has stopped. You have ceased to be, and are not continuing a journey in any other form.