to reformulate what >>2 says, welcome to the realization that in the long run, nothing really matters: you will die anyway, the sun will burn out, the universe will grow cold, empty and dead.

Nevertheless, this apparent lack of purpose gives you the ultimate freedom to decide what matters to you, what will be the goals of your existence. You have a short period of life in which you'll be able to do what you wish, so use it wisely.

Also remember, if your heart stops beating now, you won't live to do anything else. So the present heartbeat is actually your most precious and important heartbeat. Everything you are doing NOW is very precious to you. It's what you are living for real, and it's what will allow you to live other things in the future. Don't expect to live great stuff later, if you underestimate and fuck up the present.