How you view death impacts how you live life. You now have a feeling shared and contemplated by all of humankind before you, and all the humankind after you. This is the human condition.
Embrace it, come to terms with it, choose to live today and enjoy rather than worrying about that which you have no control over.
Those words are very easy to type but much harder to live.
What about counting the probable number of years you have left, and from there the number of things you have time to do? How may meals, movies, vacations left? Can you waste this rest day eating ramen in front of a bad Netflix show?
Have fun
What's a wise use of your time? Likely many many people will argue over what a wise use of time is. I've used my time in what is considered foolish ways and it turned out great. I've been carefully wise with it only for things to blow up and leave me starting over. We can never be sure of our plans for we are of mice and men.
Time does one thing for us regardless of anything we do, no matter how much we may sometimes wish otherwise. Time passes.
Based on your experience, and what people teach you, you can have a statistical average idea of what will happen if you invest time on some things (studies, work, health etc.). Of course there are some statistically improbable outcomes sometimes, for the worse and for the best, but on average you should be in the normal range.
Yes time passes, but as an educated human in a democratic developed country, you have a lot of freedom on how you want to spend it, use it!
Why assume I don't? I use my time very well by my estimation. Plenty would think I'm totally blowing it. Doesn't matter as they will be just as dust as I before long. Time will pass just the same after humanity is dead. We cannot use time. It is doing it's own thing and we are pushed along for the ride no matter what happens.
That's why I stand by my words. We can't use time, thus we can't waste it or use it wisely. We can only pass through it on its terms, never ours.
If you think you're using your time very well then it seems you are able to tell if you waste it or use it wisely for yourself. You can't control its flow but you can choose how to use the resource.
I choose to believe I am. I'm not using the time though. You cannot use it is the entire point. No matter what you do, no matter how you feel about it, no matter if you even exist anymore, time continues. Hell, you're used by time far more than you'll ever be able to use it. There is no wise use of time or waste. There is only passage.
Also, what you might think of as wise, I might think of as an absolute waste of a life. Too many differing opinions to nail down what the fuck a wise use of time is. We get to decide that little lie for ourselves. Regardless, there is a waiting future where everything we thought important is nothing but dust and ash.
I used to think like you. Life taught me better. You'll learn too, in time.
So, why don't you just wait for your death on your bed? It's not even waiting, because you can't use time, even for waiting, so I guess you are already dead. Spooky!