It’s hard not to root for an independently produced film showcasing a talented comic who has been waiting years for his moment to shine. But it’s all the more disappointing when the film nearly makes the case for why he hasn’t had a starring role before.

Jeff Garlin hits all the right notes as the main character in “I Want Someone To Eat Cheese With,” but his homage to the Ernest Borgnine film “Marty” elicits more pity than humor.

Mr. Garlin plays James, a mostly out of work 39-year-old who lives with his mother and has watched his once-promising acting career stall for 20 years. To add insult to injury, a group of Chicago producers are recasting a modern adaptation of the 1955 slacker film “Marty” and won’t even consider him for the lead role. After James is dumped by his agent, his girlfriend, and his improv troupe, he is forced to sit on the sidelines as boy-band heartthrob Aaron Carter gets the role of James’s lifetime.

Like Mr. Borgnine’s Oscar-winning film, “I Want Someone To Eat Cheese With” follows the travails of a man failing at life. But this version hedges so close to Mr. Garlin’s real life that the humor edges on malevolent.

Mr. Garlin directs himself here, and his sad-sack humor overwhelms the film. The veteran of Chicago’s Second City theater has seldom broken out of buddy roles on-screen, but he’s highly regarded in comic circles for his impeccable timing and improvisational skills — which serve him well alongside Larry David on HBO’s “Curb Your Enthusiasm.” But focusing the burden of the plot on an overweight comedian who is dealt ego blows with alarming frequency seems like overkill. Moments of levity are too far apart and often feel forced.

James lives a life of minor and major embarrassments. From living with his mother to the roles he is offered, to the lectures from his grocery store clerk about his weight, Mr. Garlin’s character is constantly confronted with his own failings. He finally meets a pretty girl (Sarah Silverman) willing to sleep with him, and her interest in finding “someone to eat cheese with” propels the story line of the film. But before Ms. Silverman can flip between bipolar personality traits (a skill at which she is so adept it is often hard to tell if she is acting), James finds out that she only slept with him because she had never been with a fat guy before. Watching him show up at her door with flowers to learn this is just painful.

Like 2005’s “The Aristocrats,” “I Want Someone To Eat Cheese With” seems like a film made by comics for comics. Mr. Garlin has filled it with cameos by his talented comedian friends, but their roles often seem like attempts to buoy the script for investors. In addition to Ms. Silverman’s manic Beth, Amy Sedaris appears as a creepy guidance counselor, Richard Kind is James’s heartless agent, Joey Slotnick is an equally under-employed actor with a pirate costume to lend out, and Bonnie Hunt is James’s improbably beautiful love interest. The comedians all adeptly maneuver their shticks, but aside from Ms. Hunt, their screen time is cobbled together more to showcase their talents than to advance the plot.

“I Want Someone To Eat Cheese With” wallows in the shadows of “Marty,” and while it is often funny to watch Mr. Garlin poke fun at himself, the humor at times borders on abuse. Mr. Garlin has injected the film with some amusing vignettes, and his talents as a comedian inspire confidence that he will achieve success as a director. Just perhaps with a bit less of himself in center screen.