I'm 44. I was a convert at the young age of about 17. I didn't really wake up to the TTATT until about a year ago. It is very hard to let go of "the dream" as I call it. Eternal youth, etc.... Very hard to think about just being gone. I've come to the conclusion that there is one of two realities awaiting us at the end. Either 1. death just as JW's believe. Eternal nonexistence. Or 2. Something else happens. What that something else is is anyone's guess.
All I can do NOW is to live in the moment. Enjoy each day to the fullest. I continue to be a good person. I dont' harm others, I try to be good and fair to everyone even those I don't like. I know that if there is a God at the end I will be able to look him in the eye and say "I did my best" and he will know I'm not lying.
Humans have dealt with this "existential crisis" from the time we became self aware, and through all of it no one has any real answers. We find ourselves in this very real situation where we live and KNOW we will one day die. It's no wonder "religion" was created by the human mind to deal with it. Much easier to believe in some fantasy at the end than to deal with the reality that death is the end for real.
Best of luck to you OP. We're all in the same sinking boat so let's have a party while it's going down!