A Gramercy Park doctor convicted of running a lucrative pill mill blamed his crimes on his “caring nature,” prosecutors said before he was sentenced Friday to 5¹/₂ years in prison.

Hector Castro, 53, was convicted last month of selling oxycodone prescriptions for $125 a pop, with some of the pills landing on the black market.

“He says he is not a greedy person but . . . a caring man who has become involved because of his caring nature,” said prosecutor Jeffrey Linehan.

Castro told Manhattan Supreme Court Justice Kirke Bartley Jr. that he was “devastated” over the conviction.