Miguel Perez told reporters on Monday that he feels physically good but "very confused".
Perez was escorted to Texas on Friday from the US-Mexican border and handed a statement to the Mexican authorities. Perez says a truck took him to an Indiana airport. He was then flown to Brownsville, Texas, ICE said.
When he got off the plane, Perez said he had arrived at a "place that looked like an office."
"I did not know it was already the bridge to get to the other side," he said, adding that he walked through a door that closed quickly behind him. "When I went back, they told me that it's all over."
"Although I'm free, there's not much pleasure in being free," said Perez, 39. [Peaches]
Perez has been in the custody of the agency since 201
The deportation follows an earlier decision by the US authorities to refuse Miguel Perez's application for citizenship for conviction for serious crimes despite his service and the PTSD he has caused.
Perez, his family and followers, including Senator Tammy Duckworth of Illinois, had argued that his military service for the country earned him the right to stay in the United States and to receive psychosocial treatment for PTSD and drug abuse.
"This case is one A tragic example of what can happen if national immigration policy is more hatred than logic and ICE does not feel responsible to anyone, "Duckworth said in a statement after reports of the deportation of Perez. "At least, Miguel could have exhausted all his legal options before being driven out of the country under a veil of secrecy."
Perez was born in Mexico and legally arrived in the United States at the age of eight when his father, Miguel Perez Sr., a semi-professional soccer player, moved the family to Chicago for a job offer, Perez told CNN previously. He has two children born in the United States. His parents and sister are now naturalized American citizens, and another sister is a born American citizen.
It's a complicated case. Perez said that what he saw and experienced in Afghanistan tore his life off the rails, leading to heavy drinking, drug addiction, and ultimately, condemnation.
"After the second tour, there was more alcohol and that was also when I tried some drugs," Perez said last month. "But the addiction really started after I came back to Chicago when I got home because I did not feel very sociable."
In 2010, he served in Cook County, Ill., On charges of delivering more than 2 pounds of cocaine to a covert investigator. He was sentenced to 15 years and his green card was revoked. He had served half of his sentence when ICE began deportation.
Perez said he was surprised to have detained ICE and mistakenly believed that recruiting the Army would automatically give him US citizenship, according to his lawyer Chris Bergin. His retroactive application for citizenship was denied earlier this month. While there are provisions for speeding up the naturalization process of the troops, a key requirement is that the claimant be "of a good moral character" and that the drug conviction be sufficient to influence the decision against his request, Bergin said.
Perez joined the army in 2001, just months before 9/11. He worked from October 2002 to April 2003 and from May to October 2003 in Afghanistan, according to his lawyer. He left the army in 2004 with a general dismissal after being caught smoking marihuana on the base.
Perez went on a hunger strike earlier this year, saying he feared deportation would mean death. Apart from not getting the treatment he needs, he told CNN that he feared that Mexican drug cartels would try to recruit him because of his combat experience, and that he would murder him if he did not cooperate.
"If they condemn me to certain death, and I will die, why then die in a place I have not been home for a long time?" he asked.
CNN's Marilia Brocchetto, Amir Vera, Maria Santana, Ralph Ellis and Marlena Baldacci contributed to this report.