Los Angeles- Actor Tom Sizemore, whose once-promising Hollywood career went into freefall because of drug addiction and a domestic violence conviction, admitted in court Friday that he had violated many of the terms of his probation, including use of a prosthetic device to mask his continued drug use. He was ordered to remain in a rehabilitation facility for at least the next eight weeks.

Los Angeles County Superior Court Judge Paula Adele Mabrey also issued Sizemore a stern warning: Breach her orders and the 43-year-old actor, who appeared in such hit films as “Saving Private Ryan” and “Black Hawk Down,” could be sent to state prison.

“I’m not making any promises; I’m not making any deals,” Mabrey told the actor.

Sizemore, who showed up late to court, has been on probation since he was convicted of felony drug possession last fall. He is in the process of appealing his conviction for assaulting former girlfriend Heidi Fleiss.

The judge ordered Sizemore confined 24 hours a day on the grounds of Las Encinas Hospital in Pasadena until he returns to her court Sept. 15. Mabrey told the actor he is not to leave the facility without authorization.

“It seems harsh, but it’s not,” a subdued Sizemore said Friday as he left the courtroom.

It was a far cry from the exuberant tone he struck in March, when another judge handed him a 17-month jail sentence for repeatedly failing drug tests while on probation in another case but allowed the actor to remain free on bail pending appeal. At that time, Sizemore left the court shouting, “I won! I’m free!”

Sizemore voluntarily checked into Las Encinas on July 11, one day before he failed to show up for a hearing on his probation violation case in Mabrey’s court. A bench warrant was issued for his arrest, but Sizemore was given until Friday to appear.

In court, Sizemore admitted he had used a prosthetic device called a Whizzinator to fake a urine test May 25, a charge that he had repeatedly denied, and also admitted he did not comply with the judge’s order last month that he undergo testing at least once every three days.

Outside court, defense attorney Michael J. Rovell said Sizemore’s legal woes can be traced to “chronic depression” as a result of substance abuse.

“He’s on medication [now] for both depression and to be weaned off [the painkiller] Vicodin, which he has a prescription for,” he said.