Americans are dying — earlier than they have been and often at their own hands.

According to the Centers for Disease Control and Prevention’s 2017 tally, there has been a dramatic rise in the numbers of U.S. deaths by suicide and drug overdose.

As Tamar Lapin noted in the New York Post recently, “The last time the U.S. experienced this long of a general decline in life expectancy was in the late 1910s when the Spanish influenza and World War I killed nearly 1 million Americans.” This time we’re doing it to ourselves.

Suicide is hard to combat. Often there are no signs. It’s quiet and hidden until its devastation is out in the open. There is rarely a particular cause to blame. Two recent cases highlight the bedeviling ­nature of the problem.

“SNL” star Pete Davidson gave the world a scare over the weekend with a cryptic Instagram post in which he said: “I really don’t want to be on this earth anymore.”

Davidson has received an outpouring of support and been accounted for. Not so for Jessica Starr. Last week, the 35-year-old Detroit meteorologist took her own life. A successful TV journalist and mother of two decided she couldn’t live anymore. It could happen to anyone — and it does.

The spike in the number of people taking their own lives is a public-health emergency. It’s something we have to combat — and not just when the victims are famous.

After high-profile suicides, like those of Anthony Bourdain and Kate Spade, we’re bombarded with stories about how to detect the signs of someone in trouble and how to help. But we need to be doing more on a regular basis to support those around us who are struggling.

One wider issue is that Americans have lost the ability to cope. The power to persevere and go on is an important one to develop. It helps to have people to turn to in times of trouble.

Let’s be the people who step in when someone is hurting or in trouble. Let’s put down our phones and laptopsand make connections on our blocks and in our neighborhoods.

But many Americans are bereft of people to lean on. The demise of tight-knit communities has had a profound effect on us. We’re increasingly living our lives on the internet, alone amid vast digital crowds. Social media has replaced socializing. We’re all guilty of staring too often at our phones. We curl up at night with the latest Chrome browser.

The loneliness is killing us.

“Baby boomers are aging alone more than any generation in U.S. history,” Janet Adamy and Paul Overberg wrote in The Wall Street Journal a few days ago. “The resulting loneliness is a looming public-health threat.” The statistics are stark: “About one in 11 Americans age 50 and older lacks a spouse, partner or living child, census figures and other research show.”

Unsurprisingly, that’s also the age group that has the highest rate of suicide and an increasing rate of drug addiction.

The economy is booming. Crime has fallen dramatically all over the country. We’re richer and safer than ever.

Yet we’re in the middle of this terrible malaise.

We’re angry, lashing out online and in videos ,we take of each other having outbursts in the real world. We’re treating each other like we’re in a video game, swiping on faces and forming virtual mobs to attack anyone who says anything we don’t like.

Last month, I argued that the decline in the amount of sex we’re having is a terrible sign for our civilization. It’s all part of the same problem. We’re not connecting.

An op-ed in The New York Times by Arthur Brooks a few weeks ago noted that Americans are suffering from an “epidemic of loneliness.” Brooks cited a large-scale survey by the insurance company Cigna, in which nearly half of respondents said “they sometimes or always feel alone or ‘left out.’ ” More than 10 percent of respondents reported that “zero people know them well.”

That’s a lot of people adrift without anyone to cling to. In 2019, let’s work on being kinder to each other.

Let’s be the people who step in when someone is hurting or in trouble. Let’s put down our phones and laptops and make connections on our blocks and in our neighborhoods.

Let’s seek out the lonely, the outcasts. Let 2018’s victims open our eyes to the desperation all around us.

We’re literally dying without each other.