Hayden Panettiere appeared to still be in the throes of addiction just three months ago as she desperately tried to reset her life, we’re told. In May, the “Nashville” actress was visiting her hit show’s namesake town to promote her memoir, “This Is Me.” Sources told Page Six that while there, she was allegedly seeking out whippets and booze with an insider claiming she attempted to have nitrous oxide delivered to her hotel, only to be denied. Security at the hotel, located in downtown Nashville, allegedly “stopped a [delivery service] order to her hotel room, which was several industrial grade nitrous oxide cans that she was planning on…