Many Post readers have wondered where I’ve been these last few months as the planet’s most narcissistic personalities, from Hillary Clinton to Mayor Bill de Blasio — and Anthony Weiner and Harvey Weinstein and Kevin Spacey and . . . — flail about without comment from me. I know this because I’ve received an avalanche of email, voice mail, snail mail, smoke signals, all asking where the devil I’m hiding, and when I’m coming back. If I’m coming back.

It’s time to come clean.

I have multiple sclerosis.

I was diagnosed with this crippling condition back in 2008, when I visited a neurologist after the fingers of my left hand started tingling and I stumbled on the street. Several times. But I kept my MS a secret for as long as I was able, withdrawing into a state of denial and working through bouts of severe exhaustion, convincing myself it wasn’t getting any worse. And then, it got worse.

Early last year, I broke my left hip. My refusal to face reality only intensified.

After a surgeon inserted titanium into the spot in which the joint used to reside, a staffer at the rehabilitation facility to which I was sent to practice things like getting out of bed asked me what happened. I cracked that I’d been in a bar fight. That was far sexier than the truth: I woke up one morning, limped into the bathroom, and landed on the hard tile floor with a thud so violent, it shook the entire building.

Afterward, I returned to work full-time. But some things had changed irrevocably.

Now I move around my apartment with the aid of a walker. When I go outside, which is far less often than ever before, I ride in a wheelchair. Sometimes, it’s pushed by my 18-year-old daughter, the same one I pushed around in a stroller as a child. The irony is not lost on me.

Zipping down the street rapidly, like a New Yorker, is more than a form of transportation or exercise to me. It’s a great, spiritual joy. Crossing the Brooklyn Bridge on foot, sometimes aboard high heels that enhanced a good pair of legs, was a passion I indulged at least once a week.

No more heels now. No more bridge. And the sun I used to worship? Heat knocks me to the floor until I withdraw, vampire-like, into the air conditioning.

Once, I was a lightning-fast typist. Now I’m all about hunt-and-peck, mainly using my almost-working right index finger. The gym is in the rearview.

At least I’ve been able to watch virtually every postseason baseball game on TV, with the exception of the American League Wild Card game, which I attended at Yankee Stadium, cheating on my loveable losers, the New York Mets. During the singing of the national anthem, I struggled to my feet and warbled along, off-key. I wouldn’t miss it.

In more than 28 years at The Post, nearly 25 as a columnist, I have brought readers slices of the world from my perspective. I’ve witnessed greatness — traveling to South Africa for the presidential election of Nelson Mandela — and grave injustice: the double-murder acquittal of OJ Simpson in Los Angeles. Once I was a yuge fan of Donald Trump, but I soured on our current president somewhat with his boasted “p—y’’ grab. (But I voted for him anyway. What choice did I have?)

On Sept. 11, 2001, I watched the Twin Towers fall from my rooftop in Brooklyn, before going to work, telling the stories of the dead and the living. And this Halloween, I watched news reports, with equal parts horror and disgust, about an ISIS-loving immigrant monster armed with a rented truck who allegedly massacred eight innocents and injured more than a dozen on a lower Manhattan bike lane. New York, the city I love, is still under attack.

It’s been my duty and my privilege to take on politicians, celebs and all manner of villains, which may be redundant, as well as to tell the stories of ordinary folks, such as Stephanie Packer. The terminally ill California woman is resisting today’s right-to-die culture, rejecting the suicide pills offered by her medical insurer in order to stay alive for her husband and four kids.

This big reveal has been difficult to write because it’s about someone I’m not accustomed to dishing about publicly. It’s about me. I realize that millions of people the world over suffer from MS, grapple with terrible afflictions, endure grisly accidents, become victims of crimes, natural disasters or human-caused carnage, leaving them in even worse physical shape than MS is leaving me. The last thing I want is to be considered some kind of inspiration. There’s nothing heroic about having my body quit working properly before I’m done using it.

But my mind is still sharp (though my enemies will disagree). And I’m not going anywhere.

I’ll be writing for this newspaper, just not as frequently as I once did. This is not goodbye.