Why don't you believe in the experience after dying ?
It's a scary feeling if you can grasp it. Grasping non-existence from within existence is difficult, I've consciously tried to do it and succeeded a couple of times, but it's fleeting and both times it affected my breathing and heart rate in a similar way to fear or panic or pain.
That being said, you can't just assume that existence is bounded by your living memories. You might as well have been everything instead of nothing prior to being spawned and you just don't remember it.
I was going to raise that, but couldn't find a short enough way to describe it properly. Something like:
Existence beyond what you can actually remember doesn't matter because it's outside any bounds of practical discussion; it should be excluded from consideration. The same way it's impossible to predict anything 'before the big bang' because we only have 'after the big bang' as useful evidence. There is no way to verify any continuity if you can't remember it or if there is no evidence of it. There's no guarantee you can even comprehend what it could be, 'you' as a concept may not even exist and it's unlikely to be relate-able to anything in this living world. Maybe you return to being 0.00001% of the collective consciousness of the universe, or any other crackpot thing anyone wants to suggest. Flying Spaghetti Monster.".
I do personally believe the latter part. I did not mean to suggest the before/after experience was going to look anything like your current one.
Its the difference between:
"I see nothing when I close my eyes" (actually you 'see' darkness over time)
and...
"I see nothing through my elbow" (You really don't see anything through your elbow because the capacity for it just doesn't exist.)
Even our basic perception of time is mediated by the structure of our brains... and without that there's no difference between one second and a trillion^trillion years.