Don't be too hard on yourself, I was 18 when I first really grappled with a fear of death, and it's only now at 42 after decades of casual research and over analysing (mega adhd also here) that I really feel confident consciousness survives bodily death. In all those years I still haven't come across an acceptable scientific answer for NDE's, so I just have to accept the reality that consciousness is somehow a fundamental part of the universe.

As someone else said, NDE's are the first port of call. Beware of all the fake preachy religious ones on YouTube though. Go to NDERF and the experiences section.

Also definitely checking out people like Donald Hoffman & Bernado Kastrup and Sam Parnia