TAMPA, Fla. (Reuters) - After 13 years of military service that included deployments to Iraq and Afghanistan, Indiana National Guard reservist Cameron St. Andrew felt crushed on Wednesday by President Donald Trump’s decision to ban transgender soldiers. The sergeant first class, who transitioned to living as a man while on active duty, said getting kicked out of the military two years before his planned retirement could mean losing many of his pension and healthcare benefits, and even harm his chances of being hired again. “Why serve a country that doesn’t want me? It breaks my heart, to be honest,” said St. Andrew, 37, of Indianapolis. Despite the devastating effect Trump’s move could have on him, he said he was more concerned about younger soldiers who were earlier in their careers and transition. “You pull that rug out from under them after they have this false sense of security, that could really throw them into a downward spiral,” he said.  The Republican president’s announcement, made through a series of Twitter posts, upended years of efforts to eliminate barriers to military service on the basis of sexual orientation or gender identity. Just last year, the Pentagon ended a prohibition keeping transgender people from serving openly. Trump, who cited “tremendous medical costs and disruption”  for the ban, did not specify how it would be implemented. It remained unclear whether the policy would apply to existing transgender service members or new transgender recruits.  The president’s action was condemned by rights groups and some lawmakers in both parties, who called it discrimination with purely political motives. The move was praised by conservative activists and some Republicans. “I have a lot of service members that are scared that their careers are over with,” said Navy Lieutenant Commander Blake Dremann, who leads a support organization working with actively serving transgender military members. “Right now, they still have their jobs and we will continue to work to make sure that policy doesn’t change.” The Pentagon said only that it was working on developing guidance following Trump’s tweets. St. Andrew said he did not know he was transgender when he enlisted, eager to serve his country after the attacks of Sept. 11, 2001. After an impoverished childhood in a small town in Michigan, he wanted to give back to the nation whose welfare system had kept him clothed and fed. Several years into his military service, he began reflecting on his gender identity. He said he struggled with the anxiety that accompanied the fear of being outed and losing his job. “They pound into you this thing of selfless service,” he said. “So you do that for a few years, and then you come out socially or to a few close people and that gives you some relief, but you still have to hide what you are.” He said he received support from his commanders and peers through his transition and found that few accommodations were needed. He already was discreet in changing facilities and had trained for the male physical fitness requirements. Still, anticipating changes like Trump’s ban coming, St. Andrew resigned from full-time service after the November election. He now wonders if his part-time reservist status is in jeopardy. “I try to be tough about it,” he said, but added: “It breaks your spirit down.” “Transgender people are serving today knowing that their leader frankly doesn’t trust them,” said retired Colonel Sheri Swokowski, 67, of Windsor, Wisconsin, the highest-ranking openly transgender veteran. “The bottom line is that this does great harm to people who simply want to serve their country.” Sergeant Sam Hunt, an electrician serving in the Nevada Army National Guard, said people had long referred to him as a man. He thought he could serve openly as such after former Democratic President Barack Obama lifted the transgender ban. Earlier this month, he learned that the Department of Defense had approved his transition to male from female. “Until told otherwise, I will continue serving this nation and state, as I have since 2009,” he said in a statement. 