A HEARTSICK Ben Affleck has spun out of control — gambling almost every night, say concerned pals.

Exclusive ENQUIRER photos, taken February 3 at the Commerce Casino in Los Angeles, show Ben intensely focused on his favorite pastime — high-stakes poker.

The Oscar winner’s string of bad luck — including his devastating breakup with J.Lo and successive box-office bombs — has sent him on a downward spiral that has friends fearing a return to his old self-destructive lifestyle.

“Our concern is that Ben isn’t dealing with his recent problems and that he’s throwing away good money after bad in a gambling whirlwind that could lead to him going back to booze,” a close pal of the actor told The ENQUIRER. “It seems like Ben has been out gambling pretty much every night since his breakup with Jennifer.

“He doesn’t hang out with his best buddy Matt Damon like he used to and now that he doesn’t have Jennifer around he’s got way too much free time on his hands.” His last two films, “Paycheck” and “Gigli,” were major disappointments.

Putting even more pressure on Ben, the industry will be closely watching the box-office results of his latest movie with Jennifer, “Jersey Girl” — which is already getting bad buzz.

Friends are very concerned, but fear if they try to counsel Ben, he’ll just shut them out of his life, divulged his close pal.

“We’re just watching him — and watching him closely. It’s hard to watch a friend go down in flames. What nobody wants is to see Ben hit rock bottom.”

During Ben’s February 3 trip to the Commerce Casino, it was clear he went to gamble seriously — not party, an eyewitness told The ENQUIRER.

“This is the very first time that I’ve seen him out gambling all alone.

“I’ve seen Ben at most of the casinos in Los Angeles and Las Vegas and he usually has a few people with him.

“The thing that struck me was that Ben wasn’t his usual confident and happy self. He seemed depressed.”

On another recent occasion at the Los Angeles-area Hustler Casino, Ben threw himself so heavily into gambling the evening turned into a disaster. Playing poker until the wee hours of the morning, he wound up losing every penny he had on him — literally!

When he left, he had to borrow money from a friend to pay the parking attendant to get his car.

Lady Luck has been a poor replacement for J.Lo. Concluded Ben’s close pal: “If he’s not busy working on a film, he’s often out doing what he loves — playing poker.

“Most gamblers drink, and up to this point Ben has been good about not going back down that road again. But he’s very vulnerable.”