I'm gonna skip the columnist response, and jump right to "stop getting drunk on alcohol" as step one. Then (re-)watch the episode of "The Good Place" where Chidi becomes a nihilist and makes chili with marshmallow Peeps.

"It could be that the purpose of your life is to serve as a warning to others." -- "Mistakes" demotivator, Despair.com

That yawning void in your soul that constantly whispers to you, "your life is meaningless, and nothing you do matters"? That's exactly what connects you with every other human that has ever lived. Most people who start to notice it just cover it up with a concert poster, or a salacious pin-up, or a photo of a sailboat, or a religious icon, just to avoid looking into it, and hearing it, and having all vitality and joy drain away through it.

But it's still there. It's not wrong. Your life really is meaningless, and nothing you do matters.

"Man is born. Man lives. Man dies. And it's all vanity." -- "Thrills", Cake

There is nothing about your life that had enough inherent value to waste. It just is what it was, the sum of all you were before. And it won't be exactly what you wanted it to be, because of entropy and psychology. You can spackle over the hole with anything that comes to hand, and desperately try to forget it's there, or you can let it remain, droning that high-pitched whine, from all the substance in your life getting sucked out into its vacuum.

A lot of what people do is, in essence, lying to each other, to save one another from that existential torment. Listen to a song on the radio? That's 3 minutes you can't hear the Hole. Watch a movie? That's 90 minutes of not staring into the Hole. Raise a kid? Heck, that's good for almost 20 years. Your Hole isn't any bigger than anyone else's. It has exactly the same amount of nothing in it. No matter what you pour into it, you're never going to fill it up--alcohol, drugs, sex, religion, entertainment, politics; they all get swallowed up in the end. If you accept that it will always be there, no matter what you do, you can slowly acclimate yourself to it. Try it on for size. Tell yourself: "I'm going to die, and everything I am will one day be forgotten."

"Look on my works, ye mighty, and despair." -- "Ozymandias", PB Shelley

So what's the point of living? Why don't we just lie down and never get up again? Why don't we lose ourselves in endless pursuit of cheap thrills and chemical highs? Because that's against the rules of the LARP game many of us play called "Being Grown-Ass Adults in the Real World". Some people do quit, and stop following the rules, and that's their choice. If you want your life to be yours, you'll just have to come up with your own purpose for it. No one is scoring points for being more noble or more visionary. You won't get judged by anyone or anything that matters for aiming too low, or not making enough progress on any given day.

Even if you don't come up with a purpose right away, you can still go through the motions of survival until you do. If you live another day, that still makes you just as good as any other animal. The cat gets it. Suck up to the human just a little bit, and they'll give you food and take away your poop. Suck up to the employer just a little bit, and they'll give you money to buy food and toilet service. If you can love your cat for doing nothing at all you consider important, some other human can certainly love you for the same level of accomplishment. (That is, if being loved is something you actually want.)

You don't have to be what other people want you to be. You don't even have to be what the person you used to be wanted to become. You don't have to live a life of greatness. You don't have to live a life devoid of meaning. The rules only apply to you if you want to play. Nobody else can be you but you, so you might as well get started.