Freed Marine veteran Robert Gilman has arrived back on American soil — with his painfully gaunt appearance proof of how he was left “near-death” from years of abuse in a brutal Russian prison, according to his family and US officials. Gilman, 32, was greeted with milkshakes and hamburgers when he touched down at Dulles airport on the outskirts of Washington, DC late Tuesday, hours after President Trump announced the US had secured his pardon from Russian President Vladimir Putin without a broader prison swap. Gilman looked pale and haggard as he posed with an American flag on his flight back…