It is interesting to read what you wrote. Some points as a reaction:
"I know that one day I'm going to die". Yes, and most people ignore it and push this insight away. You know who deals with this topic over and over, that is Buddhism. You might be open to investigate what they have to say. The rest of what you wrote also reminds me of what Buddhism has to say.
"I'm completely clueless what I could potentially change while there's still time. And the worst part is, compared to most of humanity, I'm very privileged."
Again, as I understand it, the buddhists think our live as a human is like a very fine boat, very precious. The Buddhists think we needed many lives to get to this point in the Karma circle. Sounds stupid, but just think how long evolution took to create you, how many of your parents and anchestors had to have how much luck, and voila, here you are! Bummer, not? And you know, just for a short time, and then what for. So the Buddhists think, you have kind of an obligation and responsibility, to make good use of this precious boat. They say, yes, it is urgent, not much time left.
For you it is meaning (maybe). For other it is happiness. For others yet something else. What is wrong to spend a whole life about what would or could be meaningful, or maybe there is nothing, or maybe there does not need to be something, or maybe there is something. Nothing to loose, not. Btw, here is a story I heard from Ken McLeod online in a talk:
It goes like this, a sage is sitting on the side of the street, and Alexander the Great comes along with his army. He sees the sage, and asks him, what do you do the whole day? And the Sage says I am contemplating/meditating/do nothing (I forgot the detail), and Alexander shakes his head and says, what's the point of that. And then the sage asks Alexander, and what do you do the whole day? And Alexander says, I am building an empire! And the sage says, but what for?
So if you haven't found meaning for yourself, at least you are honest about it, and maybe you know already what you are looking for.
The above mentioned Ken McLeod has written a book about Buddhism, that puts it into the context of our Western culture. I once gave a copy to a Chinese, and she said after reading it, the concepts are easy to understand, but hard to remember. For me it is the other way around, very counter intuitive to understand. I gave the book someone else too, and when she saw the book she said, "ah, you are a searcher". Maybe I am, and so far I haven't found anything better or a contradiction in it. So that is my best lead so far, maybe you would find it worthwhile to look into this area too (the book is BTW "Wake Up To Your Life", there is also a web site with lot's of transcribed talks: https://unfetteredmind.org/).
(disclaimer: meditation can be also potentially harmfull, as e.g. "terrifying" thoughts could be even more amplified and leading to a real or deeper crisis.)
Anyway, good luck (to everybody).