Nick Lachey has been ordered to attend anger management and Alcoholics Anonymous meetings after going off on a paparazzo in Los Angeles ... TMZ has confirmed.

Nick flew off the handle last year after spotting a woman who was filming his wife and himself after a night out a Mastro's in Bev Hills. Nick was enraged and caught on camera reaching for the woman's phone.

The L.A. County D.A. tells TMZ ... Lachey was never charged with a crime ... instead, the D.A. has a diversion program where someone can avoid prosecution ... in Nick's case, he won't be charged with assault and battery if he attends AA and anger management.

The woman, Jody Santos, spoke to Daily Mail about the incident, saying, "He's had plenty of time to apologize, but instead he just figured I would go away. What he did was wrong. Attempting to bust his fist through my car window when all I was doing was taking photographs of him. He should have been thanking me for the free publicity. I mean, really. Talk about an oversized ego."