Cameron Douglas wants another chance.

The heroin-addicted son of actor Michael Douglas says he’s “saturated in my own shame and penitence” as he awaits sentencing tomorrow for possessing drugs in jail.

In a handwritten letter to the judge, Cameron begged for “the opportunity to build myself and gain the tools I need to shape my future.”

“I feel so strongly, for the first time in my life, that I am truly ripe for positive reform and real achievement,” he says in the Manhattan federal court filing.

Douglas, 33, who turned rat and got five years in jail following his 2009 arrest for dealing meth, noted that he has “been battling this disease of addiction, as you know, for more than half of my life.”