Art by smbc-comics
Consciousness is often said to disappear in deep, dreamless sleep. We argue that this assumption is oversimplified. Unless dreamless sleep is defined as unconscious from the outset there are good empirical and theoretical reasons for saying that a range of different types of sleep experience, some of which are distinct from dreaming, can occur in all stages of sleep.
Pubmed Articles
Does Consciousness Disappear in Dreamless Sleep?
Sciencealert Article We Were Wrong About Consciousness Disappearing in Dreamless Sleep, Say Scientists
Not having something in the first place and losing something you have are two different things. It's like saying to someone who just lost their partner "don't feel bad, for the first n years of your life you didn't have a partner and you were fine"
Additionally, it's not billions of years of nothing. It's an eternity of nothing. Billions of years may as well be the blink of an eye relative to eternity.
God, I'm getting anxious just talking about it.