Jeffrey Epstein’s former Manhattan cellmate says guards at the lockup have been threatening him since the financier’s death, according to a legal filing by his attorneys Tuesday asking a judge to move him to a new prison. Hulking ex-cop Nicholas Tartaglione — who briefly bunked with Epstein at the Metropolitan Correctional Center — has been told by various guards there to “shut up,” “stop talking” and “stop complaining,” as questions swirled about how the accused sex trafficker was able to commit suicide in federal custody, Tartaglione attorney Bruce Barket says in a letter to White Plains federal Judge Kenneth Karas.