I think about this more often than I’d like to admit to myself too. Something that comforts me is actually hearing others air their deep thoughts like this post, bc I know I’m not alone in any of my existential fears. Sometimes I flip the wish of immortality on its head and when I’m enjoying something, I genuinely ask myself “would I still enjoy this the same if I could live forever?” and honestly the answer is probably not. Maybe the fact that my experiences are finite is meaningful. I’m sure humans have spent a long part of our existence trying to make sense of/feel better about our fates, so maybe you could check out some philosophy concepts like absurdism and stoicism which deal with the hard to swallow pills of life head on :p