Patrick Kennedy, fresh from his second stint in drug rehab, yesterday said he's building recovery support networks .....and will continue to undergo treatment for his addiction to painkillers. ........ the younger son of Sen. Ted Kennedy - entered the drug and alcohol treatment at the Mayo Clinic May 5, a day after he slammed his Mustang into a security barrier near the U.S. Capitol. An admitted binge drinker and pain-pill abuser, Kennedy, 38, had been treated at the clinic over the Christmas holidays.........Kennedy told reporters, "I know that I am doing everything I need to do to succeed."