I had an experience while extremely high on magic mushrooms. I was completely and totally convinced I was going to die. It was just before a fireworks display With utmost certainty I knew when the fireworks started I would die. I was terrified. I started going over everything i'd done in my life, everything i'd regretted, all the times i'd acted shitty to people, just everything.
During that time, I didn't realize until later, different layers of my personality were stripping away and each layer was a new thought about my life.
Then the fireworks started...I didn't die. I rememer.I didn't really feel relief...just happiness and a new feeling that just existing and making the best od life was good enough.
Since then i've found my attitude towards a lot of things has changed. I used to worry about my health a lot, not quite hypochondriac but sometimes pretty close, i'd get overwhelmed with anxiety about dying from different things. In all the years since then I haven't worried about it any more.
I find little things that would frustrate me or i'd put a lot of energy into worrying about don't bother me any more. Generally my interactions with people.have improved. I find i expect less from them now while at the same time I find myself generally caring about people's lives and the things that happen to them more than I used to.
I also lost interest in watching graphically violent movies or just senseless violence on general.
I dunno...I know it's not the same as a real near death experience but reading your comment really made me think of that time.